A260584 Number of ways to place 4n rooks on n X n board, 4 rooks in each row and each column, multiple rooks in a cell allowed, and exactly 4 rooks below the main diagonal.

1, 42, 1152, 22785, 358784, 4848569, 59160195, 674020718, 7332379979, 77311947872, 798116114567, 8122264310217, 81865063934240, 819786478839348, 8173571362926773, 81256681626746819, 806240597786756436, 7989356540290573170

Offset

2,2

Comments

a(n) is the number of minimal multiplex juggling patterns of period n using exactly 4 balls when we can catch/throw up to 4 balls at a time. (Minimal in the sense that the throws are between 0 and n-1.)

Links

Colin Barker, Table of n, a(n) for n = 2..1000

E. Banaian, S. Butler, C. Cox, J. Davis, J. Landgraf and S. Ponce A generalization of Eulerian numbers via rook placements, arXiv:1508.03673 [math.CO], 2015.

Formula

G.f.: -(25340000*x^25 - 218339000*x^24 + 967516125*x^23 - 3006320955*x^22 + 7236534214*x^21 - 13729556248*x^20 + 20397063058*x^19 - 23597394968*x^18 + 21251854412*x^17 - 14962982713*x^16 + 8335966059*x^15 - 3793119227*x^14 + 1513380019*x^13 - 584800410*x^12 + 226357446*x^11 - 80585779*x^10 + 23590993*x^9 - 5268629*x^8 + 855872*x^7 - 97502*x^6 + 7700*x^5 - 464*x^4 + 26*x^3 - x^2)/(196000000*x^26 - 2903600000*x^25 + 20460490000*x^24 - 91266464000*x^23 + 289327787000*x^22 - 693785336400*x^21 + 1307696973825*x^20 - 1987649503130*x^19 + 2479934403745*x^18 - 2572088215962*x^17 + 2237510543313*x^16 - 1642726164623*x^15 + 1021902480875*x^14 - 539757845397*x^13 + 242151721153*x^12 - 92151943921*x^11 + 29657096575*x^10 - 8031745172*x^9 + 1817290072*x^8 - 340120209*x^7 + 51938261*x^6 - 6350073*x^5 + 605172*x^4 - 43205*x^3 + 2168*x^2 - 68*x + 1).

Mathematica

CoefficientList[Series[-(25340000 x^23 -218339000 x^22 + 967516125 x^21 - 3006320955 x^20 + 7236534214 x^19 - 13729556248 x^18 + 20397063058 x^17 - 23597394968 x^16 + 21251854412 x^15 - 14962982713 x^14 + 8335966059 x^13 - 3793119227 x^12 + 1513380019 x^11 - 584800410 x^10 + 226357446 x^9 - 80585779 x^8 + 23590993 x^7 - 5268629 x^6 + 855872 x^5 - 97502 x^4 + 7700 x^3 - 464 x^2 + 26 x^1 - 1)/(196000000 x^26 - 2903600000 x^25 + 20460490000 x^24 - 91266464000 x^23 + 289327787000 x^22 - 693785336400 x^21 + 1307696973825 x^20 - 1987649503130 x^19 + 2479934403745 x^18 - 2572088215962 x^17 + 2237510543313 x^16 - 1642726164623 x^15 + 1021902480875 x^14 - 539757845397 x^13 + 242151721153 x^12 - 92151943921 x^11 + 29657096575 x^10 - 8031745172 x^9 + 1817290072 x^8 - 340120209 x^7 + 51938261 x^6 - 6350073 x^5 + 605172 x^4 - 43205 x^3 + 2168 x^2 -68 x + 1), {x, 0, 20}], x] (* Vincenzo Librandi, Aug 06 2015 *)

Crossrefs

Cf. A260575, A260582, A260583, A260585, A260727.

Sequence in context: A016094 A004361 A264178 * A004373 A001778 A111780

Adjacent sequences: A260581 A260582 A260583 * A260585 A260586 A260587

Keyword

nonn

Author

Jacob Landgraf, Jul 29 2015

Status

approved