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 1-4 of 4 results.

A195649 Number of ways to place 10n nonattacking kings on a 20 x 2n chessboard.

Original entry on oeis.org

11264, 5266069, 714611200, 50123713793, 2335042206624, 82425144219429, 2383116363555182, 59315924213143597, 1314578079936797520, 26568150968269086211, 498306336520679626558, 8788579757709800395287, 147246060712874767006100, 2362334876238883501403023
Offset: 1

Views

Author

Vaclav Kotesovec, Sep 22 2011

Keywords

Links

Crossrefs

Column k=10 of A350819.
Cf. A018807, A195654, A195659.

Formula

Recurrence order is 1318.

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).

Links

Crossrefs

Cf. A137432, A195653, A195654, A195650, A195660.

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).

Links

Crossrefs

Cf. A137432, A195653, A195654, A195655, A195651, A195661.

Formula

Recurrence order is 4248.

A195659 Number of ways to place 10n nonattacking kings on a vertical cylinder 20 X 2n.

Original entry on oeis.org

2048, 148352, 3076180, 33175486, 239238888, 1314160492, 5937279840, 23174548666, 80812754568, 257860425672, 766319864440, 2149806985106, 5753007728148, 14807729805472, 36902750545260, 89523360235366, 212335537312668, 494171055510052, 1131839140825580
Offset: 1

Views

Author

Vaclav Kotesovec, Sep 22 2011

Keywords

Comments

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

Links

Crossrefs

Cf. A195654, A195649, A137432.

Formula

Recurrence: a(n) = 4*a(n-11) - 40*a(n-10) + 181*a(n-9) - 489*a(n-8) + 876*a(n-7) - 1092*a(n-6) + 966*a(n-5) - 606*a(n-4) + 264*a(n-3) - 76*a(n-2) + 13*a(n-1).
G.f.: -(1 + 2035*x + 121804*x^2 + 1302988*x^3 + 3919832*x^4 + 3822444*x^5 + 1204400*x^6 + 113216*x^7 + 3167*x^8 + 13*x^9)/((x-1)^9*(2*x-1)^2).
a(n) = (296191755*n - 3519976573)*2^n + 524495/2016*n^8 + 4217363/504*n^7 + 2363921/16*n^6 + 66422455/36*n^5 + 557314865/32*n^4 + 8943856601/72*n^3 + 322704776641/504*n^2 + 90034143925/42*n + 3519976574.
Showing 1-4 of 4 results.

Started in 1964 by Neil J. A. Sloane | Maintained by The OEIS Foundation Inc.

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