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A172231
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Number of ways to place 5 nonattacking wazirs on a 5 X n board.
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4
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0, 2, 174, 1998, 10741, 38438, 107004, 251354, 522528, 990816, 1748883, 2914894, 4635639, 7089658, 10490366, 15089178, 21178634, 29095524, 39224013, 51998766
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OFFSET
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1,2
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COMMENTS
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Wazir is a (fairy chess) leaper [0,1].
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LINKS
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FORMULA
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a(n) = (625*n^5-5750*n^4+23535*n^3-54202*n^2+70640*n-41616)/24, n>=4.
G.f.: x^2*(5*x^7+8*x^6+129*x^5+512*x^4+1323*x^3+984*x^2+162*x+2)/(x-1)^6. - Vaclav Kotesovec, Mar 25 2010
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MATHEMATICA
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CoefficientList[Series[x (5 x^7 + 8 x^6 + 129 x^5 + 512 x^4 + 1323 x^3 + 984 x^2 + 162 x + 2) / (x - 1)^6, {x, 0, 50}], x] (* Vincenzo Librandi, May 28 2013 *)
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CROSSREFS
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KEYWORD
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nonn,easy
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AUTHOR
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STATUS
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approved
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