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.

Showing 1-5 of 5 results.

A195654 Number of ways to place 10n nonattacking kings on a 20 X 2n cylindrical chessboard.

Original entry on oeis.org

11264, 48132, 251126, 1473764, 9434784, 64923594, 476033636, 3694894500, 30179587994, 257860425672, 2290966142762, 21042965606234, 198765197377402, 1921681775292272, 18940490557328616, 189679152583318596, 1924757095250611458, 19746535064318923758
Offset: 1

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Author

Vaclav Kotesovec, Sep 22 2011

Keywords

Comments

This cylinder is horizontal: a chessboard where it is supposed that rows 1 and 2n are in contact (number of columns = 20, number of rows = 2n).

Crossrefs

Formula

Recurrence order is 916.

A195648 Number of ways to place 9n nonattacking kings on a 18 x 2n chessboard.

Original entry on oeis.org

5120, 1501674, 144605184, 7683664202, 282359109140, 8080813574550, 193194265398240, 4035559337688370, 75925129079783308, 1314578079936797520, 21279238303065874504, 325878859655043000344, 4765036384361599508980, 67005992305769489072298, 911373843678367079288192
Offset: 1

Views

Author

Vaclav Kotesovec, Sep 22 2011

Keywords

Crossrefs

Column k=9 of A350819.

Formula

Recurrence order is 548.

A195655 Number of ways to place 11n nonattacking kings on a 22 X 2n cylindrical chessboard.

Original entry on oeis.org

24576, 106500, 565512, 3392964, 22327496, 158877948, 1212120160, 9849731140, 84719304384, 766319864440, 7241521734020, 71028444904044, 718816489322444, 7466044767879028, 79230397598482712, 855840660674700612, 9381236750764316676, 104090420921618696952
Offset: 1

Views

Author

Vaclav Kotesovec, Sep 22 2011

Keywords

Comments

This cylinder is horizontal: a chessboard where it is supposed that rows 1 and 2n are in contact (number of columns = 22, number of rows = 2n).

Crossrefs

Formula

Recurrence order is 1829.

A195656 Number of ways to place 12n nonattacking kings on a 24 X 2n cylindrical chessboard.

Original entry on oeis.org

53248, 233476, 1257754, 7682812, 51698178, 378088270, 2980927200, 25173962492, 226268016376, 2149806985106, 21437333168798, 222770819826574, 2396574908171782, 26535227773186536, 300870737118178194, 3479000496509382748, 40885324678195409820
Offset: 1

Views

Author

Vaclav Kotesovec, Sep 22 2011

Keywords

Comments

This cylinder is horizontal: a chessboard where it is supposed that rows 1 and 2n are in contact (number of columns = 24, number of rows = 2n).

Crossrefs

Formula

Recurrence order is 4248.

A195658 Number of ways to place 9n nonattacking kings on a vertical cylinder 18 X 2n.

Original entry on oeis.org

1024, 50922, 815816, 7238864, 44693472, 216134044, 877751236, 3130270224, 10105541204, 30179587994, 84719304384, 226268016376, 580363147336, 1440139184616, 3477556916828, 8210011147304, 19021962952188, 43385173057846, 97653259485592, 217359166880016
Offset: 1

Views

Author

Vaclav Kotesovec, Sep 22 2011

Keywords

Comments

Vertical cylinder: a chessboard where it is supposed that the columns 1 and 18 are in contact (number of columns = 18, number of rows = 2n)

Crossrefs

Formula

Recurrence: a(n) = -4*a(n-10) + 36*a(n-9) - 145*a(n-8) + 344*a(n-7) - 532*a(n-6) + 560*a(n-5) - 406*a(n-4) + 200*a(n-3) - 64*a(n-2) + 12*a(n-1).
G.f.: (1 + 1012*x + 38698*x^2 + 270088*x^3 + 503686*x^4 + 270112*x^5 + 37900*x^6 + 1516*x^7 + 25*x^8)/((x-1)^8*(2*x-1)^2).
a(n) = (21623809*n - 226349399)*2^n + 8913/40*n^7 + 124781/20*n^6 + 376359/4*n^5 + 977074*n^4 + 294753537/40*n^3 + 787733819/20*n^2 + 135269649*n + 226349400.
Showing 1-5 of 5 results.