A201237 Number of ways to place 3 non-attacking wazirs on an n X n toroidal board.

0, 0, 6, 208, 1300, 4908, 14112, 34112, 73008, 142700, 259908, 447312, 734812, 1160908, 1774200, 2635008, 3817112, 5409612, 7518908, 10270800, 13812708, 18316012, 23978512, 31027008, 39720000, 50350508, 63249012, 78786512, 97377708, 119484300, 145618408

Offset: 1

Author

Vaclav Kotesovec, Nov 28 2011

Keywords

• nonn

Comments

A wazir is a leaper [0,1].

Links

• V. Kotesovec, Non-attacking chess pieces, 6ed, p.402

Crossrefs

Cf. A172226, A201236, A201238, A201239, A201240, A201241, A201242.

Formula

a(n) = n^2*(n^4-15*n^2+62)/6, n>=4.

G.f.: -2*x^3 * (3*x^7 - 15*x^6 + 25*x^5 - 7*x^4 - 17*x^3 - 15*x^2 + 83*x + 3)/(x-1)^7.