9 20

9_19

9_21

Visit 9 20's page at the Knot Server (KnotPlot driven, includes 3D interactive images!) Visit 9 20's page at Knotilus! Visit 9 20's page at the original Knot Atlas!

9 20 Quick Notes

From knotilus

Knot presentations

Planar diagram presentation	X1425 X3,10,4,11 X5,14,6,15 X7,16,8,17 X11,1,12,18 X15,6,16,7 X17,13,18,12 X13,8,14,9 X9,2,10,3
Gauss code	-1, 9, -2, 1, -3, 6, -4, 8, -9, 2, -5, 7, -8, 3, -6, 4, -7, 5
Dowker-Thistlethwaite code	4 10 14 16 2 18 8 6 12
Conway Notation	[31212]

Three dimensional invariants

Symmetry type Reversible Unknotting number 2 3-genus 3 Bridge index 2 Super bridge index [math]\displaystyle{ \{4,6\} }[/math] Nakanishi index 1 Maximal Thurston-Bennequin number [-12][1] Hyperbolic Volume 9.6443 A-Polynomial See Data:9 20/A-polynomial

[edit Notes for 9 20's three dimensional invariants]

Four dimensional invariants

Smooth 4 genus [math]\displaystyle{ 2 }[/math] Topological 4 genus [math]\displaystyle{ 2 }[/math] Concordance genus [math]\displaystyle{ 3 }[/math] Rasmussen s-Invariant -4

[edit Notes for 9 20's four dimensional invariants]

Polynomial invariants

Alexander polynomial	[math]\displaystyle{ -t^3+5 t^2-9 t+11-9 t^{-1} +5 t^{-2} - t^{-3} }[/math]
Conway polynomial	[math]\displaystyle{ -z^6-z^4+2 z^2+1 }[/math]
2nd Alexander ideal (db, data sources)	[math]\displaystyle{ \{1\} }[/math]
Determinant and Signature	{ 41, -4 }
Jones polynomial	[math]\displaystyle{ 1-2 q^{-1} +4 q^{-2} -5 q^{-3} +7 q^{-4} -7 q^{-5} +6 q^{-6} -5 q^{-7} +3 q^{-8} - q^{-9} }[/math]
HOMFLY-PT polynomial (db, data sources)	[math]\displaystyle{ -z^2 a^8-a^8+2 z^4 a^6+5 z^2 a^6+2 a^6-z^6 a^4-4 z^4 a^4-5 z^2 a^4-2 a^4+z^4 a^2+3 z^2 a^2+2 a^2 }[/math]
Kauffman polynomial (db, data sources)	[math]\displaystyle{ z^3 a^{11}+3 z^4 a^{10}-z^2 a^{10}+5 z^5 a^9-5 z^3 a^9+2 z a^9+5 z^6 a^8-6 z^4 a^8+3 z^2 a^8-a^8+3 z^7 a^7-7 z^3 a^7+2 z a^7+z^8 a^6+5 z^6 a^6-16 z^4 a^6+10 z^2 a^6-2 a^6+5 z^7 a^5-12 z^5 a^5+5 z^3 a^5+z^8 a^4+z^6 a^4-11 z^4 a^4+11 z^2 a^4-2 a^4+2 z^7 a^3-7 z^5 a^3+6 z^3 a^3+z^6 a^2-4 z^4 a^2+5 z^2 a^2-2 a^2 }[/math]
The A2 invariant	[math]\displaystyle{ -q^{28}+q^{24}-q^{22}+q^{20}-q^{18}+q^{14}-q^{12}+2 q^{10}-q^8+q^6+q^4+1 }[/math]
The G2 invariant	[math]\displaystyle{ q^{148}-2 q^{146}+3 q^{144}-4 q^{142}+2 q^{140}-q^{138}-2 q^{136}+9 q^{134}-12 q^{132}+15 q^{130}-13 q^{128}+5 q^{126}+2 q^{124}-13 q^{122}+23 q^{120}-27 q^{118}+23 q^{116}-13 q^{114}-q^{112}+15 q^{110}-23 q^{108}+25 q^{106}-21 q^{104}+5 q^{102}+7 q^{100}-17 q^{98}+16 q^{96}-5 q^{94}-9 q^{92}+23 q^{90}-24 q^{88}+14 q^{86}+3 q^{84}-26 q^{82}+44 q^{80}-44 q^{78}+30 q^{76}-4 q^{74}-21 q^{72}+43 q^{70}-45 q^{68}+33 q^{66}-17 q^{64}-6 q^{62}+22 q^{60}-28 q^{58}+22 q^{56}-6 q^{54}-9 q^{52}+19 q^{50}-19 q^{48}+7 q^{46}+8 q^{44}-23 q^{42}+31 q^{40}-28 q^{38}+12 q^{36}+10 q^{34}-26 q^{32}+36 q^{30}-30 q^{28}+17 q^{26}-q^{24}-13 q^{22}+21 q^{20}-19 q^{18}+14 q^{16}-3 q^{14}-2 q^{12}+5 q^{10}-5 q^8+4 q^6-q^4+q^2 }[/math]

Further Quantum Invariants

Further quantum knot invariants for 9_20.

A1 Invariants.

Weight	Invariant
1	[math]\displaystyle{ -q^{19}+2 q^{17}-2 q^{15}+q^{13}-q^{11}+2 q^7-q^5+2 q^3-q+ q^{-1} }[/math]
2	[math]\displaystyle{ q^{52}-2 q^{50}+5 q^{46}-6 q^{44}-q^{42}+8 q^{40}-8 q^{38}-q^{36}+9 q^{34}-4 q^{32}-4 q^{30}+4 q^{28}+2 q^{26}-5 q^{24}-3 q^{22}+6 q^{20}-q^{18}-7 q^{16}+8 q^{14}+3 q^{12}-8 q^{10}+5 q^8+5 q^6-6 q^4+q^2+4-2 q^{-2} - q^{-4} + q^{-6} }[/math]
3	[math]\displaystyle{ -q^{99}+2 q^{97}-3 q^{93}+5 q^{89}+2 q^{87}-10 q^{85}+13 q^{81}-2 q^{79}-18 q^{77}+2 q^{75}+25 q^{73}-2 q^{71}-28 q^{69}-2 q^{67}+30 q^{65}+7 q^{63}-26 q^{61}-13 q^{59}+16 q^{57}+19 q^{55}-6 q^{53}-20 q^{51}-5 q^{49}+21 q^{47}+13 q^{45}-16 q^{43}-22 q^{41}+13 q^{39}+23 q^{37}-9 q^{35}-27 q^{33}+2 q^{31}+28 q^{29}+4 q^{27}-27 q^{25}-11 q^{23}+26 q^{21}+17 q^{19}-19 q^{17}-20 q^{15}+13 q^{13}+23 q^{11}-3 q^9-20 q^7-2 q^5+14 q^3+7 q-8 q^{-1} -7 q^{-3} +3 q^{-5} +5 q^{-7} -2 q^{-11} - q^{-13} + q^{-15} }[/math]
4	[math]\displaystyle{ q^{160}-2 q^{158}+3 q^{154}-2 q^{152}+q^{150}-6 q^{148}+3 q^{146}+9 q^{144}-8 q^{142}+2 q^{140}-10 q^{138}+11 q^{136}+18 q^{134}-25 q^{132}-10 q^{130}-9 q^{128}+40 q^{126}+37 q^{124}-53 q^{122}-46 q^{120}-15 q^{118}+79 q^{116}+79 q^{114}-60 q^{112}-93 q^{110}-51 q^{108}+86 q^{106}+122 q^{104}-15 q^{102}-92 q^{100}-97 q^{98}+30 q^{96}+111 q^{94}+48 q^{92}-28 q^{90}-96 q^{88}-45 q^{86}+39 q^{84}+78 q^{82}+50 q^{80}-51 q^{78}-87 q^{76}-28 q^{74}+73 q^{72}+85 q^{70}-5 q^{68}-93 q^{66}-68 q^{64}+60 q^{62}+92 q^{60}+24 q^{58}-90 q^{56}-92 q^{54}+44 q^{52}+92 q^{50}+58 q^{48}-70 q^{46}-114 q^{44}+3 q^{42}+76 q^{40}+98 q^{38}-20 q^{36}-112 q^{34}-52 q^{32}+26 q^{30}+114 q^{28}+46 q^{26}-63 q^{24}-76 q^{22}-40 q^{20}+70 q^{18}+73 q^{16}+6 q^{14}-44 q^{12}-68 q^{10}+7 q^8+44 q^6+35 q^4+4 q^2-40-19 q^{-2} +3 q^{-4} +19 q^{-6} +18 q^{-8} -8 q^{-10} -9 q^{-12} -7 q^{-14} + q^{-16} +7 q^{-18} + q^{-20} -2 q^{-24} - q^{-26} + q^{-28} }[/math]
5	[math]\displaystyle{ -q^{235}+2 q^{233}-3 q^{229}+2 q^{227}+q^{225}+q^{221}-2 q^{219}-4 q^{217}+2 q^{215}+6 q^{213}-q^{211}-8 q^{209}-5 q^{207}+10 q^{205}+15 q^{203}+8 q^{201}-18 q^{199}-46 q^{197}-15 q^{195}+50 q^{193}+81 q^{191}+32 q^{189}-77 q^{187}-147 q^{185}-73 q^{183}+114 q^{181}+236 q^{179}+133 q^{177}-137 q^{175}-326 q^{173}-232 q^{171}+119 q^{169}+420 q^{167}+350 q^{165}-68 q^{163}-460 q^{161}-464 q^{159}-46 q^{157}+443 q^{155}+556 q^{153}+176 q^{151}-353 q^{149}-573 q^{147}-306 q^{145}+198 q^{143}+514 q^{141}+400 q^{139}-23 q^{137}-388 q^{135}-422 q^{133}-140 q^{131}+213 q^{129}+390 q^{127}+262 q^{125}-44 q^{123}-304 q^{121}-338 q^{119}-100 q^{117}+215 q^{115}+354 q^{113}+205 q^{111}-132 q^{109}-361 q^{107}-261 q^{105}+87 q^{103}+349 q^{101}+288 q^{99}-49 q^{97}-356 q^{95}-311 q^{93}+44 q^{91}+362 q^{89}+335 q^{87}-17 q^{85}-376 q^{83}-381 q^{81}-16 q^{79}+378 q^{77}+426 q^{75}+83 q^{73}-346 q^{71}-472 q^{69}-180 q^{67}+280 q^{65}+491 q^{63}+277 q^{61}-165 q^{59}-467 q^{57}-379 q^{55}+21 q^{53}+390 q^{51}+433 q^{49}+129 q^{47}-259 q^{45}-429 q^{43}-260 q^{41}+102 q^{39}+361 q^{37}+336 q^{35}+55 q^{33}-241 q^{31}-332 q^{29}-176 q^{27}+97 q^{25}+275 q^{23}+234 q^{21}+28 q^{19}-167 q^{17}-220 q^{15}-117 q^{13}+61 q^{11}+167 q^9+140 q^7+22 q^5-87 q^3-119 q-65 q^{-1} +23 q^{-3} +75 q^{-5} +67 q^{-7} +15 q^{-9} -32 q^{-11} -45 q^{-13} -29 q^{-15} +4 q^{-17} +25 q^{-19} +22 q^{-21} +5 q^{-23} -6 q^{-25} -11 q^{-27} -9 q^{-29} + q^{-31} +5 q^{-33} +3 q^{-35} + q^{-37} -2 q^{-41} - q^{-43} + q^{-45} }[/math]

A2 Invariants.

Weight	Invariant
1,0	[math]\displaystyle{ -q^{28}+q^{24}-q^{22}+q^{20}-q^{18}+q^{14}-q^{12}+2 q^{10}-q^8+q^6+q^4+1 }[/math]
1,1	[math]\displaystyle{ q^{76}-4 q^{74}+8 q^{72}-12 q^{70}+22 q^{68}-36 q^{66}+46 q^{64}-56 q^{62}+72 q^{60}-84 q^{58}+84 q^{56}-82 q^{54}+77 q^{52}-62 q^{50}+32 q^{48}+4 q^{46}-43 q^{44}+90 q^{42}-132 q^{40}+168 q^{38}-192 q^{36}+198 q^{34}-190 q^{32}+158 q^{30}-126 q^{28}+82 q^{26}-30 q^{24}-18 q^{22}+57 q^{20}-82 q^{18}+106 q^{16}-110 q^{14}+104 q^{12}-84 q^{10}+70 q^8-48 q^6+29 q^4-16 q^2+8-2 q^{-2} + q^{-4} }[/math]
2,0	[math]\displaystyle{ q^{70}-q^{66}+q^{62}-3 q^{58}+q^{56}+2 q^{54}-3 q^{52}-q^{50}+4 q^{48}+3 q^{46}-4 q^{44}-q^{42}+3 q^{40}-2 q^{38}-4 q^{36}+2 q^{34}+q^{32}-4 q^{30}+q^{28}+2 q^{26}-2 q^{24}-2 q^{22}+4 q^{20}+3 q^{18}-2 q^{16}+q^{14}+5 q^{12}-2 q^8+q^6+2 q^4-1+ q^{-4} }[/math]

A3 Invariants.

Weight	Invariant
0,1,0	[math]\displaystyle{ q^{62}-2 q^{60}-q^{58}+5 q^{56}-3 q^{54}-3 q^{52}+8 q^{50}-3 q^{48}-6 q^{46}+6 q^{44}-2 q^{42}-6 q^{40}+4 q^{38}+q^{36}-2 q^{34}-q^{32}+3 q^{30}+3 q^{28}-6 q^{26}+3 q^{24}+5 q^{22}-7 q^{20}+5 q^{16}-5 q^{14}+2 q^{12}+5 q^{10}-2 q^8+2 q^6+2 q^4-q^2+1 }[/math]
1,0,0	[math]\displaystyle{ -q^{37}-q^{33}+q^{31}-q^{29}+2 q^{27}-q^{25}+q^{23}-q^{15}+q^{13}-q^{11}+2 q^9+2 q^5+q }[/math]

A4 Invariants.

Weight	Invariant
0,1,0,0	[math]\displaystyle{ q^{80}-2 q^{76}-q^{74}+2 q^{72}+2 q^{70}-2 q^{68}+5 q^{64}-6 q^{60}+2 q^{56}-6 q^{54}-3 q^{52}+3 q^{50}+q^{48}-4 q^{46}+3 q^{44}+5 q^{42}-4 q^{40}-q^{38}+7 q^{36}-7 q^{32}+4 q^{30}+3 q^{28}-4 q^{26}-3 q^{24}+3 q^{22}+q^{20}-2 q^{18}+2 q^{16}+4 q^{14}+q^{12}+q^{10}+3 q^8+q^6+q^2 }[/math]
1,0,0,0	[math]\displaystyle{ -q^{46}-q^{42}-q^{40}+q^{38}-q^{36}+2 q^{34}+q^{30}+q^{28}-q^{22}-2 q^{18}+q^{16}-q^{14}+2 q^{12}+q^{10}+q^8+2 q^6+q^2 }[/math]

B2 Invariants.

Weight	Invariant
0,1	[math]\displaystyle{ -q^{62}+2 q^{60}-3 q^{58}+5 q^{56}-7 q^{54}+7 q^{52}-8 q^{50}+7 q^{48}-6 q^{46}+4 q^{44}-4 q^{40}+8 q^{38}-11 q^{36}+14 q^{34}-15 q^{32}+15 q^{30}-13 q^{28}+10 q^{26}-7 q^{24}+3 q^{22}+q^{20}-4 q^{18}+7 q^{16}-7 q^{14}+8 q^{12}-7 q^{10}+6 q^8-4 q^6+4 q^4-q^2+1 }[/math]
1,0	[math]\displaystyle{ q^{100}-2 q^{96}-2 q^{94}+q^{92}+5 q^{90}+2 q^{88}-5 q^{86}-5 q^{84}+2 q^{82}+8 q^{80}+2 q^{78}-7 q^{76}-6 q^{74}+3 q^{72}+7 q^{70}-q^{68}-7 q^{66}-2 q^{64}+6 q^{62}+4 q^{60}-5 q^{58}-5 q^{56}+3 q^{54}+5 q^{52}-2 q^{50}-5 q^{48}+q^{46}+5 q^{44}-6 q^{40}-q^{38}+7 q^{36}+5 q^{34}-5 q^{32}-8 q^{30}+q^{28}+9 q^{26}+3 q^{24}-6 q^{22}-6 q^{20}+4 q^{18}+7 q^{16}+q^{14}-4 q^{12}-2 q^{10}+3 q^8+3 q^6-q^4-q^2+ q^{-2} }[/math]

D4 Invariants.

Weight	Invariant
1,0,0,0	[math]\displaystyle{ q^{86}-2 q^{84}+q^{82}-2 q^{80}+5 q^{78}-5 q^{76}+4 q^{74}-5 q^{72}+8 q^{70}-5 q^{68}+4 q^{66}-6 q^{64}+3 q^{62}-2 q^{60}-2 q^{58}-6 q^{54}+7 q^{52}-8 q^{50}+11 q^{48}-11 q^{46}+13 q^{44}-9 q^{42}+12 q^{40}-9 q^{38}+8 q^{36}-5 q^{34}+3 q^{32}-3 q^{30}-2 q^{28}+2 q^{26}-5 q^{24}+4 q^{22}-6 q^{20}+8 q^{18}-4 q^{16}+7 q^{14}-3 q^{12}+6 q^{10}-2 q^8+3 q^6-q^4+q^2 }[/math]

G2 Invariants.

Weight

Invariant

1,0

[math]\displaystyle{ q^{148}-2 q^{146}+3 q^{144}-4 q^{142}+2 q^{140}-q^{138}-2 q^{136}+9 q^{134}-12 q^{132}+15 q^{130}-13 q^{128}+5 q^{126}+2 q^{124}-13 q^{122}+23 q^{120}-27 q^{118}+23 q^{116}-13 q^{114}-q^{112}+15 q^{110}-23 q^{108}+25 q^{106}-21 q^{104}+5 q^{102}+7 q^{100}-17 q^{98}+16 q^{96}-5 q^{94}-9 q^{92}+23 q^{90}-24 q^{88}+14 q^{86}+3 q^{84}-26 q^{82}+44 q^{80}-44 q^{78}+30 q^{76}-4 q^{74}-21 q^{72}+43 q^{70}-45 q^{68}+33 q^{66}-17 q^{64}-6 q^{62}+22 q^{60}-28 q^{58}+22 q^{56}-6 q^{54}-9 q^{52}+19 q^{50}-19 q^{48}+7 q^{46}+8 q^{44}-23 q^{42}+31 q^{40}-28 q^{38}+12 q^{36}+10 q^{34}-26 q^{32}+36 q^{30}-30 q^{28}+17 q^{26}-q^{24}-13 q^{22}+21 q^{20}-19 q^{18}+14 q^{16}-3 q^{14}-2 q^{12}+5 q^{10}-5 q^8+4 q^6-q^4+q^2 }[/math]

.

Computer Talk

The above data is available with the Mathematica package KnotTheory`, as shown in the (simulated) Mathematica session below. Your input (in red) is realistic; all else should have the same content as in a real mathematica session, but with different formatting. This Mathematica session is also available (albeit only for the knot 5_2) as the notebook PolynomialInvariantsSession.nb.

(The path below may be different on your system, and possibly also the KnotTheory` date)

In[1]:=

AppendTo[$Path, "C:/drorbn/projects/KAtlas/"]; << KnotTheory`

Loading KnotTheory` version of August 31, 2006, 11:25:27.5625. Read more at http://katlas.math.toronto.edu/wiki/KnotTheory.

In[3]:=

K = Knot["9 20"];

In[4]:=

Alexander[K][t]

KnotTheory::loading: Loading precomputed data in PD4Knots`.

Out[4]=

[math]\displaystyle{ -t^3+5 t^2-9 t+11-9 t^{-1} +5 t^{-2} - t^{-3} }[/math]

In[5]:=

Conway[K][z]

Out[5]=

[math]\displaystyle{ -z^6-z^4+2 z^2+1 }[/math]

In[6]:=

Alexander[K, 2][t]

KnotTheory::credits: The program Alexander[K, r] to compute Alexander ideals was written by Jana Archibald at the University of Toronto in the summer of 2005.

Out[6]=

[math]\displaystyle{ \{1\} }[/math]

In[7]:=

{KnotDet[K], KnotSignature[K]}

Out[7]=

{ 41, -4 }

In[8]:=

Jones[K][q]

KnotTheory::loading: Loading precomputed data in Jones4Knots`.

Out[8]=

[math]\displaystyle{ 1-2 q^{-1} +4 q^{-2} -5 q^{-3} +7 q^{-4} -7 q^{-5} +6 q^{-6} -5 q^{-7} +3 q^{-8} - q^{-9} }[/math]

In[9]:=

HOMFLYPT[K][a, z]

KnotTheory::credits: The HOMFLYPT program was written by Scott Morrison.

Out[9]=

[math]\displaystyle{ -z^2 a^8-a^8+2 z^4 a^6+5 z^2 a^6+2 a^6-z^6 a^4-4 z^4 a^4-5 z^2 a^4-2 a^4+z^4 a^2+3 z^2 a^2+2 a^2 }[/math]

In[10]:=

Kauffman[K][a, z]

KnotTheory::loading: Loading precomputed data in Kauffman4Knots`.

Out[10]=

[math]\displaystyle{ z^3 a^{11}+3 z^4 a^{10}-z^2 a^{10}+5 z^5 a^9-5 z^3 a^9+2 z a^9+5 z^6 a^8-6 z^4 a^8+3 z^2 a^8-a^8+3 z^7 a^7-7 z^3 a^7+2 z a^7+z^8 a^6+5 z^6 a^6-16 z^4 a^6+10 z^2 a^6-2 a^6+5 z^7 a^5-12 z^5 a^5+5 z^3 a^5+z^8 a^4+z^6 a^4-11 z^4 a^4+11 z^2 a^4-2 a^4+2 z^7 a^3-7 z^5 a^3+6 z^3 a^3+z^6 a^2-4 z^4 a^2+5 z^2 a^2-2 a^2 }[/math]

Vassiliev invariants

V2 and V3:

(2, -4)

V2,1 through V6,9:

V2,1 V3,1 V4,1 V4,2 V4,3 V5,1 V5,2 V5,3 V5,4 V6,1 V6,2 V6,3 V6,4 V6,5 V6,6 V6,7 V6,8 V6,9 [math]\displaystyle{ 8 }[/math] [math]\displaystyle{ -32 }[/math] [math]\displaystyle{ 32 }[/math] [math]\displaystyle{ \frac{412}{3} }[/math] [math]\displaystyle{ \frac{68}{3} }[/math] [math]\displaystyle{ -256 }[/math] [math]\displaystyle{ -\frac{1856}{3} }[/math] [math]\displaystyle{ -\frac{224}{3} }[/math] [math]\displaystyle{ -128 }[/math] [math]\displaystyle{ \frac{256}{3} }[/math] [math]\displaystyle{ 512 }[/math] [math]\displaystyle{ \frac{3296}{3} }[/math] [math]\displaystyle{ \frac{544}{3} }[/math] [math]\displaystyle{ \frac{42751}{15} }[/math] [math]\displaystyle{ -\frac{4124}{15} }[/math] [math]\displaystyle{ \frac{64924}{45} }[/math] [math]\displaystyle{ \frac{833}{9} }[/math] [math]\displaystyle{ \frac{2911}{15} }[/math]

V_2,1 through V_6,9 were provided by Petr Dunin-Barkowski <barkovs@itep.ru>, Andrey Smirnov <asmirnov@itep.ru>, and Alexei Sleptsov <sleptsov@itep.ru> and uploaded on October 2010 by User:Drorbn. Note that they are normalized differently than V₂ and V₃.

Khovanov Homology

The coefficients of the monomials [math]\displaystyle{ t^rq^j }[/math] are shown, along with their alternating sums [math]\displaystyle{ \chi }[/math] (fixed [math]\displaystyle{ j }[/math], alternation over [math]\displaystyle{ r }[/math]). The squares with yellow highlighting are those on the "critical diagonals", where [math]\displaystyle{ j-2r=s+1 }[/math] or [math]\displaystyle{ j-2r=s+1 }[/math], where [math]\displaystyle{ s= }[/math]-4 is the signature of 9 20. Nonzero entries off the critical diagonals (if any exist) are highlighted in red.

\   r    \    j   \	-7	-6	-5	-4	-3	-2	-1	0	1	2	χ
1										1	1
-1									1		-1
-3								3	1		2
-5							3	2			-1
-7						4	2				2
-9					3	3					0
-11				3	4						-1
-13			2	3							1
-15		1	3								-2
-17		2									2
-19	1										-1

Computer Talk

Much of the above data can be recomputed by Mathematica using the package KnotTheory`. See A Sample KnotTheory` Session.

[math]\displaystyle{ \textrm{Include}(\textrm{ColouredJonesM.mhtml}) }[/math]

In[1]:=	<< KnotTheory`
Loading KnotTheory` (version of August 17, 2005, 14:44:34)...
In[2]:=	Crossings[Knot[9, 20]]
Out[2]=	9
In[3]:=	PD[Knot[9, 20]]
Out[3]=	PD[X[1, 4, 2, 5], X[3, 10, 4, 11], X[5, 14, 6, 15], X[7, 16, 8, 17], X[11, 1, 12, 18], X[15, 6, 16, 7], X[17, 13, 18, 12], X[13, 8, 14, 9], X[9, 2, 10, 3]]
In[4]:=	GaussCode[Knot[9, 20]]
Out[4]=	GaussCode[-1, 9, -2, 1, -3, 6, -4, 8, -9, 2, -5, 7, -8, 3, -6, 4, -7, 5]
In[5]:=	BR[Knot[9, 20]]
Out[5]=	BR[4, {-1, -1, -1, 2, -1, -3, 2, -3, -3}]
In[6]:=	alex = Alexander[Knot[9, 20]][t]
Out[6]=	-3 5 9 2 3 11 - t + -- - - - 9 t + 5 t - t 2 t t
In[7]:=	Conway[Knot[9, 20]][z]
Out[7]=	2 4 6 1 + 2 z - z - z
In[8]:=	Select[AllKnots[], (alex === Alexander[#][t])&]
Out[8]=	{Knot[9, 20], Knot[10, 149], Knot[11, NonAlternating, 26]}
In[9]:=	{KnotDet[Knot[9, 20]], KnotSignature[Knot[9, 20]]}
Out[9]=	{41, -4}
In[10]:=	J=Jones[Knot[9, 20]][q]
Out[10]=	-9 3 5 6 7 7 5 4 2 1 - q + -- - -- + -- - -- + -- - -- + -- - - 8 7 6 5 4 3 2 q q q q q q q q
In[11]:=	Select[AllKnots[], (J === Jones[#][q] || (J /. q-> 1/q) === Jones[#][q])&]
Out[11]=	{Knot[9, 20], Knot[11, NonAlternating, 90]}
In[12]:=	A2Invariant[Knot[9, 20]][q]
Out[12]=	-28 -24 -22 -20 -18 -14 -12 2 -8 -6 1 - q + q - q + q - q + q - q + --- - q + q + 10 q -4 q
In[13]:=	Kauffman[Knot[9, 20]][a, z]
Out[13]=	2 4 6 8 7 9 2 2 4 2 -2 a - 2 a - 2 a - a + 2 a z + 2 a z + 5 a z + 11 a z + 6 2 8 2 10 2 3 3 5 3 7 3 9 3 10 a z + 3 a z - a z + 6 a z + 5 a z - 7 a z - 5 a z + 11 3 2 4 4 4 6 4 8 4 10 4 a z - 4 a z - 11 a z - 16 a z - 6 a z + 3 a z - 3 5 5 5 9 5 2 6 4 6 6 6 8 6 7 a z - 12 a z + 5 a z + a z + a z + 5 a z + 5 a z + 3 7 5 7 7 7 4 8 6 8 2 a z + 5 a z + 3 a z + a z + a z
In[14]:=	{Vassiliev[2][Knot[9, 20]], Vassiliev[3][Knot[9, 20]]}
Out[14]=	{0, -4}
In[15]:=	Kh[Knot[9, 20]][q, t]
Out[15]=	2 3 1 2 1 3 2 3 -- + -- + ------ + ------ + ------ + ------ + ------ + ------ + 5 3 19 7 17 6 15 6 15 5 13 5 13 4 q q q t q t q t q t q t q t 3 4 3 3 4 2 3 t t 2 ------ + ------ + ----- + ----- + ----- + ---- + ---- + -- + - + q t 11 4 11 3 9 3 9 2 7 2 7 5 3 q q t q t q t q t q t q t q t q