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A201237
Number of ways to place 3 non-attacking wazirs on an n X n toroidal board.
8
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
1,3
COMMENTS
A wazir is a leaper [0,1].
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.
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Nov 28 2011
STATUS
approved