A201547 Number of ways to place 9 nonattacking wazirs on an n X n toroidal board.

0, 0, 0, 0, 250, 480916, 54916456, 1962132800, 34690541994, 385983794500, 3095143575007, 19437996015280, 100963195651565, 450398154002132, 1773257833600750, 6288010190509312, 20398342362118678, 61282868654684052, 172190699515632837, 456120623076014000

Offset

1,5

Comments

Wazir is a leaper [0,1].

Links

Table of n, a(n) for n=1..20.

V. Kotesovec, Non-attacking chess pieces

Formula

Explicit formula: n^18/362880 - n^16/2016 + 349*n^14/8640 - 467*n^12/240 + 1049629*n^10/17280 - 121049*n^8/96 + 1546301783*n^6/90720 - 346878319*n^4/2520 + 4595485*n^2/9, n>=10.

G.f.: -x^5*(18*x^23 - 854*x^22 + 15942*x^21 - 168082*x^20 + 1174353*x^19 - 5878707*x^18 + 22139332*x^17 - 65539648*x^16 + 159915785*x^15 - 334575275*x^14 + 598795512*x^13 - 842713520*x^12 + 703597341*x^11 + 289921121*x^10 - 2021527454*x^9 + 3166171570*x^8 - 1944444195*x^7 - 501647511*x^6 + 11035282966*x^5 + 6335694166*x^4 + 1000714522*x^3 + 45821802*x^2 + 476166*x + 250)/(x-1)^19.

Crossrefs

Cf. A201236, A201237, A201238, A201239, A201240, A201241, A201242, A201510.

Sequence in context: A253005 A267972 A267995 * A165281 A033449 A271581

Adjacent sequences: A201544 A201545 A201546 * A201548 A201549 A201550

Keyword

nonn

Author

Vaclav Kotesovec, Dec 02 2011

Status

approved