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.

A288026 Array read by antidiagonals: T(m,n) = number of maximal matchings in the grid graph P_m X P_n.

Original entry on oeis.org

1, 1, 1, 2, 2, 2, 2, 5, 5, 2, 3, 11, 22, 11, 3, 4, 24, 75, 75, 24, 4, 5, 51, 264, 400, 264, 51, 5, 7, 109, 941, 2357, 2357, 941, 109, 7, 9, 234, 3286, 13407, 22228, 13407, 3286, 234, 9, 12, 503, 11623, 76667, 207423, 207423, 76667, 11623, 503, 12
Offset: 1

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Author

Andrew Howroyd, Jun 04 2017

Keywords

Examples

			Table starts:
=====================================================
m\n| 1   2    3     4       5        6          7
---|-------------------------------------------------
1  | 1   1    2     2       3        4          5 ...
2  | 1   2    5    11      24       51        109 ...
3  | 2   5   22    75     264      941       3286 ...
4  | 2  11   75   400    2357    13407      76667 ...
5  | 3  24  264  2357   22228   207423    1922112 ...
6  | 4  51  941 13407  207423  3136370   47256485 ...
7  | 5 109 3286 76667 1922112 47256485 1158560776 ...
...
		

Crossrefs

Main diagonal is A287595.
Rows 1-3 are A182097(n+2), A286945, A288028.

A033509 Number of matchings in graph P_{6} X P_{n}.

Original entry on oeis.org

1, 13, 733, 31687, 1453535, 65805403, 2989126727, 135658637925, 6158217253688, 279533139565077, 12688781322524383, 575975678462394151, 26145024935911561519, 1186789728933332428003, 53871436268769248658909
Offset: 0

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Author

Keywords

References

  • Per Hakan Lundow, "Computation of matching polynomials and the number of 1-factors in polygraphs", Research reports, No 12, 1996, Department of Mathematics, Umea University.

Crossrefs

Column 6 of triangle A210662.
Bisection (even part) gives A260035.

Formula

G.f.: (1 -23*x -311*x^2 +3891*x^3 +12057*x^4 -218447*x^5 +315889*x^6 +2997721*x^7 -8754480*x^8 -13467571*x^9 +66016499*x^10 +14684235*x^11 -240612231*x^12 +56233657*x^13 +496137395*x^14 -207743591*x^15 -612805499*x^16 +303976032*x^17 +458919487*x^18 -249194245*x^19 -206819317*x^20 +123372421*x^21 +54160427*x^22 -37223601*x^23 -7443809*x^24 +6708699*x^25 +338040*x^26 -686517*x^27 +29377*x^28 +36273*x^29 -3521*x^30 -861*x^31 +109*x^32 +7*x^33 -x^34) / (1 -36*x -576*x^2 +6080*x^3 +42422*x^4 -453004*x^5 -443404*x^6 +12931566*x^7 -25517604*x^8 -83558644*x^9 +295510396*x^10 +154307596*x^11 -1335612340*x^12 +274712602*x^13 +3235975264*x^14 -1630080704*x^15 -4669345206*x^16 +2978277152*x^17 +4169343006*x^18 -2919950172*x^19 -2310327672*x^20 +1717916424*x^21 +777289050*x^22 -626694028*x^23 -149620588*x^24 +141424642*x^25 +13835164*x^26 -19237868*x^27 -94620*x^28 +1503868*x^29 -81796*x^30 -62874*x^31 +5736*x^32 +1224*x^33 -138*x^34 -8*x^35 +x^36). - Sergey Perepechko, May 04 2013

A033510 Number of matchings in graph P_{7} X P_{n}.

Original entry on oeis.org

1, 21, 2356, 196785, 17525619, 1539222016, 135658637925, 11945257052321, 1052091957273408, 92657526436631289, 8160498611028648795, 718704019165239462736, 63297158846544276862187, 5574656798624151746571203, 490966794038702258639391536, 43240039834820302340627322251
Offset: 0

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Author

Keywords

Crossrefs

Column 7 of triangle A210662.

Extensions

Terms a(13) and beyond from Andrew Howroyd, Apr 18 2021

A033512 Number of matchings in graph P_{9} X P_{n}.

Original entry on oeis.org

1, 55, 24342, 7594361, 2548684656, 842518533590, 279533139565077, 92657526436631289, 30721240815429999078, 10185111919160666118608, 3376771882017849561260401, 1119528305492897225312120742, 371166848426649070379972358241, 123056076089539426001744759117065
Offset: 0

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Author

Keywords

References

  • Per Hakan Lundow, "Computation of matching polynomials and the number of 1-factors in polygraphs", Research reports, No 12, 1996, Department of Mathematics, Umea University.

Crossrefs

Column k=9 of A210662.

A033513 Number of matchings in graph P_{10} X P_{n}.

Original entry on oeis.org

1, 89, 78243, 47177097, 30734932553, 19711134149599, 12688781322524383, 8160498611028648795, 5249581929453966097649, 3376771882017849561260401, 2172138783673094193937750015, 1397239543795157686038029989037, 898783117890438425073750503319527
Offset: 0

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Author

Keywords

Crossrefs

Column k=10 of A210662.

A033514 Number of matchings in graph P_{11} X P_{n}.

Original entry on oeis.org

1, 144, 251498, 293066688, 370635224561, 461148537211748, 575975678462394151, 718704019165239462736, 897032469743945346623442, 1119528305492897225312120742, 1397239543795157686038029989037, 1743829823240164494694386437970640
Offset: 0

Views

Author

Keywords

References

  • Per Hakan Lundow, "Computation of matching polynomials and the number of 1-factors in polygraphs", Research reports, No 12, 1996, Department of Mathematics, Umea University.

Crossrefs

Column k=11 of A210662.
Previous Showing 11-16 of 16 results.