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The Alternating Knot 818Visit 818's page at the Knot Server (KnotPlot driven, includes 3D interactive images!) Visit 818's page at Knotilus! |
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PD Presentation: | X6271 X8394 X16,11,1,12 X2,14,3,13 X4,15,5,16 X10,6,11,5 X12,7,13,8 X14,10,15,9 |
Gauss Code: | {1, -4, 2, -5, 6, -1, 7, -2, 8, -6, 3, -7, 4, -8, 5, -3} |
DT (Dowker-Thistlethwaite) Code: | 6 8 10 12 14 16 2 4 |
Minimum Braid Representative:
Length is 8, width is 3 Braid index is 3 |
A Morse Link Presentation:
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3D Invariants: |
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Alexander Polynomial: | - t-3 + 5t-2 - 10t-1 + 13 - 10t + 5t2 - t3 |
Conway Polynomial: | 1 + z2 - z4 - z6 |
Other knots with the same Alexander/Conway Polynomial: | {924, K11n85, K11n164, ...} |
Determinant and Signature: | {45, 0} |
Jones Polynomial: | q-4 - 4q-3 + 6q-2 - 7q-1 + 9 - 7q + 6q2 - 4q3 + q4 |
Other knots (up to mirrors) with the same Jones Polynomial: | {...} |
A2 (sl(3)) Invariant: | q-12 - 2q-10 - q-6 - q-4 + 4q-2 + 1 + 4q2 - q4 - q6 - 2q10 + q12 |
HOMFLY-PT Polynomial: | - a-2 + a-2z2 + a-2z4 + 3 - z2 - 3z4 - z6 - a2 + a2z2 + a2z4 |
Kauffman Polynomial: | a-4z4 - 4a-3z3 + 4a-3z5 + a-2 + 3a-2z2 - 9a-2z4 + 6a-2z6 + a-1z - 9a-1z3 + 3a-1z5 + 3a-1z7 + 3 + 6z2 - 20z4 + 12z6 + az - 9az3 + 3az5 + 3az7 + a2 + 3a2z2 - 9a2z4 + 6a2z6 - 4a3z3 + 4a3z5 + a4z4 |
V2 and V3, the type 2 and 3 Vassiliev invariants: | {1, 0} |
Khovanov Homology:
(The squares with yellow highlighting are those on the "critical diagonals", where j-2r=s+1 or j-2r=s+1, where s=0 is the signature of 818. Nonzero entries off the critical diagonals (if any exist) are highlighted in red.) |
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n | Coloured Jones Polynomial (in the (n+1)-dimensional representation of sl(2)) |
2 | q-12 - 4q-11 + 2q-10 + 13q-9 - 21q-8 - 4q-7 + 41q-6 - 38q-5 - 20q-4 + 69q-3 - 43q-2 - 36q-1 + 81 - 36q - 43q2 + 69q3 - 20q4 - 38q5 + 41q6 - 4q7 - 21q8 + 13q9 + 2q10 - 4q11 + q12 |
3 | q-24 - 4q-23 + 2q-22 + 9q-21 - q-20 - 24q-19 - 10q-18 + 55q-17 + 27q-16 - 79q-15 - 73q-14 + 108q-13 + 130q-12 - 121q-11 - 199q-10 + 119q-9 + 266q-8 - 105q-7 - 322q-6 + 74q-5 + 374q-4 - 53q-3 - 389q-2 + 10q-1 + 411 + 10q - 389q2 - 53q3 + 374q4 + 74q5 - 322q6 - 105q7 + 266q8 + 119q9 - 199q10 - 121q11 + 130q12 + 108q13 - 73q14 - 79q15 + 27q16 + 55q17 - 10q18 - 24q19 - q20 + 9q21 + 2q22 - 4q23 + q24 |
4 | q-40 - 4q-39 + 2q-38 + 9q-37 - 5q-36 - 4q-35 - 30q-34 + 14q-33 + 66q-32 + 10q-31 - 20q-30 - 173q-29 - 36q-28 + 217q-27 + 184q-26 + 77q-25 - 483q-24 - 344q-23 + 280q-22 + 558q-21 + 530q-20 - 729q-19 - 930q-18 - 11q-17 + 880q-16 + 1297q-15 - 647q-14 - 1490q-13 - 605q-12 + 916q-11 + 2042q-10 - 297q-9 - 1774q-8 - 1196q-7 + 714q-6 + 2508q-5 + 97q-4 - 1785q-3 - 1595q-2 + 427q-1 + 2659 + 427q - 1595q2 - 1785q3 + 97q4 + 2508q5 + 714q6 - 1196q7 - 1774q8 - 297q9 + 2042q10 + 916q11 - 605q12 - 1490q13 - 647q14 + 1297q15 + 880q16 - 11q17 - 930q18 - 729q19 + 530q20 + 558q21 + 280q22 - 344q23 - 483q24 + 77q25 + 184q26 + 217q27 - 36q28 - 173q29 - 20q30 + 10q31 + 66q32 + 14q33 - 30q34 - 4q35 - 5q36 + 9q37 + 2q38 - 4q39 + q40 |
5 | q-60 - 4q-59 + 2q-58 + 9q-57 - 5q-56 - 8q-55 - 10q-54 - 6q-53 + 25q-52 + 59q-51 + 15q-50 - 78q-49 - 132q-48 - 88q-47 + 108q-46 + 310q-45 + 309q-44 - 82q-43 - 588q-42 - 694q-41 - 160q-40 + 793q-39 + 1380q-38 + 769q-37 - 888q-36 - 2171q-35 - 1762q-34 + 471q-33 + 2960q-32 + 3222q-31 + 409q-30 - 3440q-29 - 4844q-28 - 1921q-27 + 3420q-26 + 6480q-25 + 3843q-24 - 2833q-23 - 7798q-22 - 5983q-21 + 1728q-20 + 8665q-19 + 8083q-18 - 291q-17 - 9075q-16 - 9861q-15 - 1314q-14 + 9043q-13 + 11334q-12 + 2801q-11 - 8752q-10 - 12285q-9 - 4191q-8 + 8219q-7 + 13045q-6 + 5245q-5 - 7664q-4 - 13289q-3 - 6232q-2 + 6937q-1 + 13529 + 6937q - 6232q2 - 13289q3 - 7664q4 + 5245q5 + 13045q6 + 8219q7 - 4191q8 - 12285q9 - 8752q10 + 2801q11 + 11334q12 + 9043q13 - 1314q14 - 9861q15 - 9075q16 - 291q17 + 8083q18 + 8665q19 + 1728q20 - 5983q21 - 7798q22 - 2833q23 + 3843q24 + 6480q25 + 3420q26 - 1921q27 - 4844q28 - 3440q29 + 409q30 + 3222q31 + 2960q32 + 471q33 - 1762q34 - 2171q35 - 888q36 + 769q37 + 1380q38 + 793q39 - 160q40 - 694q41 - 588q42 - 82q43 + 309q44 + 310q45 + 108q46 - 88q47 - 132q48 - 78q49 + 15q50 + 59q51 + 25q52 - 6q53 - 10q54 - 8q55 - 5q56 + 9q57 + 2q58 - 4q59 + q60 |
6 | q-84 - 4q-83 + 2q-82 + 9q-81 - 5q-80 - 8q-79 - 14q-78 + 14q-77 + 5q-76 + 18q-75 + 64q-74 - 33q-73 - 91q-72 - 142q-71 - 12q-70 + 79q-69 + 240q-68 + 452q-67 + 89q-66 - 372q-65 - 894q-64 - 700q-63 - 286q-62 + 804q-61 + 2153q-60 + 1773q-59 + 283q-58 - 2351q-57 - 3566q-56 - 3627q-55 - 523q-54 + 4727q-53 + 7138q-52 + 5812q-51 - 686q-50 - 7202q-49 - 12365q-48 - 9094q-47 + 2360q-46 + 13358q-45 + 18364q-44 + 10619q-43 - 3858q-42 - 21807q-41 - 26164q-40 - 12005q-39 + 11102q-38 + 31253q-37 + 31409q-36 + 13077q-35 - 21636q-34 - 43154q-33 - 36283q-32 - 5200q-31 + 33899q-30 + 51716q-29 + 39414q-28 - 7797q-27 - 49853q-26 - 59515q-25 - 29741q-24 + 23826q-23 + 62146q-22 + 63867q-21 + 12957q-20 - 45038q-19 - 73279q-18 - 51845q-17 + 7933q-16 + 62275q-15 + 79256q-14 + 31297q-13 - 34984q-12 - 77600q-11 - 65954q-10 - 6236q-9 + 57322q-8 + 86030q-7 + 43450q-6 - 25252q-5 - 76697q-4 - 73175q-3 - 16550q-2 + 51151q-1 + 87709 + 51151q - 16550q2 - 73175q3 - 76697q4 - 25252q5 + 43450q6 + 86030q7 + 57322q8 - 6236q9 - 65954q10 - 77600q11 - 34984q12 + 31297q13 + 79256q14 + 62275q15 + 7933q16 - 51845q17 - 73279q18 - 45038q19 + 12957q20 + 63867q21 + 62146q22 + 23826q23 - 29741q24 - 59515q25 - 49853q26 - 7797q27 + 39414q28 + 51716q29 + 33899q30 - 5200q31 - 36283q32 - 43154q33 - 21636q34 + 13077q35 + 31409q36 + 31253q37 + 11102q38 - 12005q39 - 26164q40 - 21807q41 - 3858q42 + 10619q43 + 18364q44 + 13358q45 + 2360q46 - 9094q47 - 12365q48 - 7202q49 - 686q50 + 5812q51 + 7138q52 + 4727q53 - 523q54 - 3627q55 - 3566q56 - 2351q57 + 283q58 + 1773q59 + 2153q60 + 804q61 - 286q62 - 700q63 - 894q64 - 372q65 + 89q66 + 452q67 + 240q68 + 79q69 - 12q70 - 142q71 - 91q72 - 33q73 + 64q74 + 18q75 + 5q76 + 14q77 - 14q78 - 8q79 - 5q80 + 9q81 + 2q82 - 4q83 + q84 |
7 | q-112 - 4q-111 + 2q-110 + 9q-109 - 5q-108 - 8q-107 - 14q-106 + 10q-105 + 25q-104 - 2q-103 + 23q-102 + 16q-101 - 46q-100 - 91q-99 - 120q-98 + q-97 + 194q-96 + 228q-95 + 305q-94 + 159q-93 - 265q-92 - 667q-91 - 1062q-90 - 701q-89 + 318q-88 + 1373q-87 + 2402q-86 + 2319q-85 + 673q-84 - 1836q-83 - 4899q-82 - 5994q-81 - 3738q-80 + 996q-79 + 7628q-78 + 11884q-77 + 10820q-76 + 3971q-75 - 8456q-74 - 19772q-73 - 23149q-72 - 15565q-71 + 3896q-70 + 26043q-69 + 39541q-68 + 36591q-67 + 11339q-66 - 25804q-65 - 57204q-64 - 66358q-63 - 39973q-62 + 12511q-61 + 68336q-60 + 100926q-59 + 83792q-58 + 19179q-57 - 66151q-56 - 133172q-55 - 137679q-54 - 70621q-53 + 42889q-52 + 153359q-51 + 194934q-50 + 139172q-49 + 3442q-48 - 154136q-47 - 245138q-46 - 216584q-45 - 71245q-44 + 130992q-43 + 279711q-42 + 293462q-41 + 153405q-40 - 85147q-39 - 293239q-38 - 360206q-37 - 240305q-36 + 21900q-35 + 284890q-34 + 410240q-33 + 322851q-32 + 50497q-31 - 258503q-30 - 441071q-29 - 393503q-28 - 123370q-27 + 219717q-26 + 454109q-25 + 448852q-24 + 189820q-23 - 176053q-22 - 453071q-21 - 487746q-20 - 245868q-19 + 132559q-18 + 443069q-17 + 513256q-16 + 289741q-15 - 94142q-14 - 428270q-13 - 527350q-12 - 322834q-11 + 60878q-10 + 412390q-9 + 535248q-8 + 347117q-7 - 34348q-6 - 396718q-5 - 537790q-4 - 365850q-3 + 10559q-2 + 381625q-1 + 539297 + 381625q + 10559q2 - 365850q3 - 537790q4 - 396718q5 - 34348q6 + 347117q7 + 535248q8 + 412390q9 + 60878q10 - 322834q11 - 527350q12 - 428270q13 - 94142q14 + 289741q15 + 513256q16 + 443069q17 + 132559q18 - 245868q19 - 487746q20 - 453071q21 - 176053q22 + 189820q23 + 448852q24 + 454109q25 + 219717q26 - 123370q27 - 393503q28 - 441071q29 - 258503q30 + 50497q31 + 322851q32 + 410240q33 + 284890q34 + 21900q35 - 240305q36 - 360206q37 - 293239q38 - 85147q39 + 153405q40 + 293462q41 + 279711q42 + 130992q43 - 71245q44 - 216584q45 - 245138q46 - 154136q47 + 3442q48 + 139172q49 + 194934q50 + 153359q51 + 42889q52 - 70621q53 - 137679q54 - 133172q55 - 66151q56 + 19179q57 + 83792q58 + 100926q59 + 68336q60 + 12511q61 - 39973q62 - 66358q63 - 57204q64 - 25804q65 + 11339q66 + 36591q67 + 39541q68 + 26043q69 + 3896q70 - 15565q71 - 23149q72 - 19772q73 - 8456q74 + 3971q75 + 10820q76 + 11884q77 + 7628q78 + 996q79 - 3738q80 - 5994q81 - 4899q82 - 1836q83 + 673q84 + 2319q85 + 2402q86 + 1373q87 + 318q88 - 701q89 - 1062q90 - 667q91 - 265q92 + 159q93 + 305q94 + 228q95 + 194q96 + q97 - 120q98 - 91q99 - 46q100 + 16q101 + 23q102 - 2q103 + 25q104 + 10q105 - 14q106 - 8q107 - 5q108 + 9q109 + 2q110 - 4q111 + q112 |
Computer Talk. The data above can be recomputed by Mathematica using the package KnotTheory`. Following setup, the sample Mathematica session below reproduces most of the above data (Mathematica system prompts in blue, human input in red, Mathematica output in black):
In[1]:= |
<< KnotTheory` |
Loading KnotTheory` (version of August 30, 2005, 10:15:35)... | |
In[2]:= | PD[Knot[8, 18]] |
Out[2]= | PD[X[6, 2, 7, 1], X[8, 3, 9, 4], X[16, 11, 1, 12], X[2, 14, 3, 13], > X[4, 15, 5, 16], X[10, 6, 11, 5], X[12, 7, 13, 8], X[14, 10, 15, 9]] |
In[3]:= | GaussCode[Knot[8, 18]] |
Out[3]= | GaussCode[1, -4, 2, -5, 6, -1, 7, -2, 8, -6, 3, -7, 4, -8, 5, -3] |
In[4]:= | DTCode[Knot[8, 18]] |
Out[4]= | DTCode[6, 8, 10, 12, 14, 16, 2, 4] |
In[5]:= | br = BR[Knot[8, 18]] |
Out[5]= | BR[3, {-1, 2, -1, 2, -1, 2, -1, 2}] |
In[6]:= | {First[br], Crossings[br]} |
Out[6]= | {3, 8} |
In[7]:= | BraidIndex[Knot[8, 18]] |
Out[7]= | 3 |
In[8]:= | Show[DrawMorseLink[Knot[8, 18]]] |
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Out[8]= | -Graphics- |
In[9]:= | #[Knot[8, 18]]& /@ {SymmetryType, UnknottingNumber, ThreeGenus, BridgeIndex, SuperBridgeIndex, NakanishiIndex} |
Out[9]= | {FullyAmphicheiral, 2, 3, 3, 4, 2} |
In[10]:= | alex = Alexander[Knot[8, 18]][t] |
Out[10]= | -3 5 10 2 3 13 - t + -- - -- - 10 t + 5 t - t 2 t t |
In[11]:= | Conway[Knot[8, 18]][z] |
Out[11]= | 2 4 6 1 + z - z - z |
In[12]:= | Select[AllKnots[], (alex === Alexander[#][t])&] |
Out[12]= | {Knot[8, 18], Knot[9, 24], Knot[11, NonAlternating, 85], > Knot[11, NonAlternating, 164]} |
In[13]:= | {KnotDet[Knot[8, 18]], KnotSignature[Knot[8, 18]]} |
Out[13]= | {45, 0} |
In[14]:= | Jones[Knot[8, 18]][q] |
Out[14]= | -4 4 6 7 2 3 4 9 + q - -- + -- - - - 7 q + 6 q - 4 q + q 3 2 q q q |
In[15]:= | Select[AllKnots[], (J === Jones[#][q] || (J /. q-> 1/q) === Jones[#][q])&] |
Out[15]= | {Knot[8, 18]} |
In[16]:= | A2Invariant[Knot[8, 18]][q] |
Out[16]= | -12 2 -6 -4 4 2 4 6 10 12 1 + q - --- - q - q + -- + 4 q - q - q - 2 q + q 10 2 q q |
In[17]:= | HOMFLYPT[Knot[8, 18]][a, z] |
Out[17]= | 2 4 -2 2 2 z 2 2 4 z 2 4 6 3 - a - a - z + -- + a z - 3 z + -- + a z - z 2 2 a a |
In[18]:= | Kauffman[Knot[8, 18]][a, z] |
Out[18]= | 2 3 3 -2 2 z 2 3 z 2 2 4 z 9 z 3 3 + a + a + - + a z + 6 z + ---- + 3 a z - ---- - ---- - 9 a z - a 2 3 a a a 4 4 5 5 3 3 4 z 9 z 2 4 4 4 4 z 3 z 5 > 4 a z - 20 z + -- - ---- - 9 a z + a z + ---- + ---- + 3 a z + 4 2 3 a a a a 6 7 3 5 6 6 z 2 6 3 z 7 > 4 a z + 12 z + ---- + 6 a z + ---- + 3 a z 2 a a |
In[19]:= | {Vassiliev[2][Knot[8, 18]], Vassiliev[3][Knot[8, 18]]} |
Out[19]= | {1, 0} |
In[20]:= | Kh[Knot[8, 18]][q, t] |
Out[20]= | 5 1 3 1 3 3 4 3 3 - + 5 q + ----- + ----- + ----- + ----- + ----- + ---- + --- + 3 q t + 4 q t + q 9 4 7 3 5 3 5 2 3 2 3 q t q t q t q t q t q t q t 3 2 5 2 5 3 7 3 9 4 > 3 q t + 3 q t + q t + 3 q t + q t |
In[21]:= | ColouredJones[Knot[8, 18], 2][q] |
Out[21]= | -12 4 2 13 21 4 41 38 20 69 43 36 81 + q - --- + --- + -- - -- - -- + -- - -- - -- + -- - -- - -- - 36 q - 11 10 9 8 7 6 5 4 3 2 q q q q q q q q q q q 2 3 4 5 6 7 8 9 10 > 43 q + 69 q - 20 q - 38 q + 41 q - 4 q - 21 q + 13 q + 2 q - 11 12 > 4 q + q |
Dror Bar-Natan: The Knot Atlas: The Rolfsen Knot Table: The Knot 818 |
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