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 A172228 Number of ways to place 5 nonattacking wazirs on an n X n board. 9
 0, 0, 1, 304, 10741, 127960, 870589, 4197456, 16005187, 51439096, 145085447, 369074128, 863338777, 1883786680, 3875953561, 7583888944, 14206566327, 25617069208, 44663199283, 75572017136, 124485188701, 200156902936, 314851577749, 485484612496, 735056106571, 1094434774968 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,4 COMMENTS Wazir is a (fairy chess) leaper [0,1]. LINKS Vincenzo Librandi, Table of n, a(n) for n = 1..1000 Eric Weisstein's World of Mathematics, Grid Graph Wikipedia, Fairy chess piece Wikipedia, Wazir (chess) FORMULA a(n) = (n^10-50n^8+40n^7+995n^6-1560n^5-8890n^4+21080n^3+24264n^2-97440n+59520)/120, n>=4. For any fixed value of k > 1, a(n) = n^(2k)/k! - 5/2/(k-2)!*n^(2k-2) + ... G.f.: x^3 * (6*x^11 -26*x^10 -93*x^9 +527*x^8 +490*x^7 -6710*x^6 +13630*x^5 -3954*x^4 -26364*x^3 -7452*x^2 -293*x -1) / (x-1)^11. - Vaclav Kotesovec, Apr 29 2011 MATHEMATICA CoefficientList[Series[x^2 (6 x^11 - 26 x^10 - 93 x^9 + 527 x^8 + 490 x^7 - 6710 x^6 + 13630 x^5 - 3954 x^4 - 26364 x^3 - 7452 x^2 - 293 x - 1) / (x - 1)^11, {x, 0, 50}], x] (* Vincenzo Librandi, May 28 2013 *) CROSSREFS Cf. A172225, A172226, A172227, A108792, A061998, A172129, A172136, A172140, A006506. Sequence in context: A300965 A300922 A301530 * A281329 A293092 A221117 Adjacent sequences:  A172225 A172226 A172227 * A172229 A172230 A172231 KEYWORD nonn,easy AUTHOR Vaclav Kotesovec, Jan 29 2010 EXTENSIONS Corrected a(4) and g.f., Vaclav Kotesovec, Apr 29 2011. More terms from Vincenzo Librandi, May 28 2013 STATUS approved

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Last modified December 18 20:06 EST 2018. Contains 318245 sequences. (Running on oeis4.)