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A201242
Number of ways to place 8 non-attacking wazirs on an n X n toroidal board.
8
0, 0, 0, 2, 1550, 546516, 28482279, 585632520, 6829066665, 54504255500, 331490619174, 1642426038486, 6930083422496, 25686190415144, 85541928717375, 260349711114720, 733731834393719, 1934755847570808, 4813391235753128, 11375736647373750, 25684539545337246
OFFSET
1,4
COMMENTS
Wazir is a leaper [0,1].
FORMULA
a(n) = n^2*(n^14 - 140n^12 + 8722n^10 - 313880n^8 + 7061089n^6 - 99573740n^4 + 817978188n^2 - 3033601200)/40320, n>=9.
G.f.: x^4 * (16x^21 - 566x^20 + 8182x^19 - 67700x^18 + 377824x^17 - 1531112x^16 + 4601788x^15 - 10205035x^14 + 16637339x^13 - 21628151x^12 + 32135719x^11 - 68863352x^10 + 138461546x^9 - 189569712x^8 + 133644570x^7 + 20663373x^6 - 378949513x^5 - 174710713x^4 - 19400947x^3 - 520438x^2 - 1516x - 2)/(x-1)^17.
CROSSREFS
KEYWORD
nonn
AUTHOR
Vaclav Kotesovec, Nov 28 2011
STATUS
approved