cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

Previous Showing 11-16 of 16 results.

A339118 Number of cycles in the grid graph P_6 X P_n.

Original entry on oeis.org

15, 275, 5034, 80626, 1222363, 18438929, 279285399, 4237530095, 64300829449, 975566486675, 14800469958185, 224540402345213, 3406558215857382, 51681816786790684, 784078741397570677, 11895467318139343215, 180469294422664219486, 2737947622842077799930
Offset: 2

Views

Author

Seiichi Manyama, Nov 24 2020

Keywords

Crossrefs

Programs

  • Python
    # Using graphillion
    from graphillion import GraphSet
    import graphillion.tutorial as tl
    def A(n, k):
        universe = tl.grid(n - 1, k - 1)
        GraphSet.set_universe(universe)
        cycles = GraphSet.cycles()
        return cycles.len()
    def A339118(n):
        return A(6, n)
    print([A339118(n) for n in range(2, 13)])

Formula

Empirical g.f.: -x^2 * (15 - 325*x + 3889*x^2 - 32204*x^3 + 166496*x^4 - 439661*x^5 + 117553*x^6 + 2506529*x^7 - 5691052*x^8 - 128310*x^9 + 16209330*x^10 - 15148184*x^11 - 17089827*x^12 + 28709449*x^13 + 11141815*x^14 - 27136640*x^15 - 13792528*x^16 + 20876587*x^17 + 15963209*x^18 - 11646759*x^19 - 10681356*x^20 + 3192142*x^21 + 3419602*x^22 - 252986*x^23 - 401310*x^24 - 43774*x^25 + 13852*x^26 + 2950*x^27 - 278*x^28 - 48*x^29 + 4*x^30) / ((-1 + x)^2 * (-1 + 38*x - 580*x^2 + 4945*x^3 - 26274*x^4 + 84913*x^5 - 122213*x^6 - 183068*x^7 + 1124479*x^8 - 1544617*x^9 - 1129508*x^10 + 5346947*x^11 - 3023145*x^12 - 6147688*x^13 + 6904233*x^14 + 3952819*x^15 - 5690282*x^16 - 4144167*x^17 + 3164355*x^18 + 4915006*x^19 - 1267655*x^20 - 3336331*x^21 + 82962*x^22 + 1051157*x^23 + 93428*x^24 - 119962*x^25 - 23089*x^26 + 2688*x^27 + 1368*x^28 - 34*x^29 - 30*x^30 + 2*x^31)). - Vaclav Kotesovec, Dec 09 2020

Extensions

Terms a(13) and beyond from Andrew Howroyd, Dec 08 2020

A339119 Number of cycles in the grid graph P_7 X P_n.

Original entry on oeis.org

21, 681, 23984, 692194, 18438929, 487150371, 12947640143, 345142437669, 9203308475041, 245355064111139, 6540331954247241, 174341025325354201, 4647322411026104632, 123881845810609904802, 3302270967098053652763, 88027348826922694314763, 2346510376337057464408514
Offset: 2

Views

Author

Seiichi Manyama, Nov 24 2020

Keywords

Comments

a(n+1) / a(n) tends to 26.65660630533835653493851570574867751479178653672292060740586256111131858... - Vaclav Kotesovec, Nov 24 2020

Crossrefs

Programs

  • Python
    # Using graphillion
    from graphillion import GraphSet
    import graphillion.tutorial as tl
    def A(n, k):
        universe = tl.grid(n - 1, k - 1)
        GraphSet.set_universe(universe)
        cycles = GraphSet.cycles()
        return cycles.len()
    def A339119(n):
        return A(n, 7)
    print([A339119(n) for n in range(2, 15)])

A339120 Number of cycles in the grid graph P_8 X P_n.

Original entry on oeis.org

28, 1664, 114069, 5948291, 279285399, 12947640143, 603841648931, 28251882697663, 1322310119854705, 61875355046353061, 2895006802805407868, 135448608195945754204, 6337277838067727854392, 296505504331623399871908, 13872765058478362509835979, 649072483984291902586660423
Offset: 2

Views

Author

Seiichi Manyama, Nov 24 2020

Keywords

Crossrefs

Extensions

Terms a(10) and beyond from Andrew Howroyd, Dec 08 2020

A339121 Number of cycles in the grid graph P_9 X P_n.

Original entry on oeis.org

36, 4040, 542295, 51139577, 4237530095, 345142437669, 28251882697663, 2318527339461265, 190273063549680295, 15609156135669687673, 1280305089790914190288, 105011610206669201362004, 8613171107463963712000106, 706463610718638922253288622, 57945052730138702492774189915
Offset: 2

Views

Author

Seiichi Manyama, Nov 24 2020

Keywords

Crossrefs

Programs

  • Python
    # Using graphillion
    from graphillion import GraphSet
    import graphillion.tutorial as tl
    def A(n, k):
        universe = tl.grid(n - 1, k - 1)
        GraphSet.set_universe(universe)
        cycles = GraphSet.cycles()
        return cycles.len()
    def A339121(n):
        return A(n, 9)
    print([A339121(n) for n in range(2, 15)])

A358785 Number of cycles in the grid graph P_11 X P_n.

Original entry on oeis.org

55, 23637, 12253948, 3779989098, 975566486675, 245355064111139, 61875355046353061, 15609156135669687673, 3931128009418993765997, 988808811046283595068099, 248581947999911644069460438, 62479777983071973470513443588, 15702642238437709110690166048520
Offset: 2

Views

Author

Seiichi Manyama, Nov 30 2022

Keywords

Crossrefs

Row 10 of A231829.

A358707 Number of cycles in the grid graph P_10 X P_n.

Original entry on oeis.org

45, 9779, 2577870, 439673502, 64300829449, 9203308475041, 1322310119854705, 190273063549680295, 27359264067916806101, 3931128009418993765997, 564680431992866012642342, 81106350080343571152166324, 11649258590678717543578165244, 1673159830616398545304368383554
Offset: 2

Views

Author

Seiichi Manyama, Nov 30 2022

Keywords

Crossrefs

Row 9 of A231829.
Cf. A140517.

Extensions

a(12)-a(15) from Andrew Howroyd, Jan 28 2023
Previous Showing 11-16 of 16 results.