A123615 Column 5 of triangle A123610.

1, 6, 63, 392, 1764, 6352, 19404, 52272, 127413, 286286, 601203, 1192464, 2252432, 4078368, 7116336, 12018704, 19718181, 31521798, 49228487, 75274584, 112911880, 166423400, 241382700, 344962800, 486301725, 676932006, 931282191, 1267259168

Offset

0,2

Links

G. C. Greubel, Table of n, a(n) for n = 0..1000

Formula

G.f.: P_5(x) / ((1-x)^2*(1-x^2)^2*(1-x^3)^2*(1-x^4)^2*(1-x^5)^2), with P_5(1) = 9!, where P_5(x) = (1+4*x+50*x^2+262*x^3+930*x^4+2566*x^5+5795*x^6+11156*x^7+ 18699*x^8+27712*x^9+36699*x^10+43696*x^11+46988*x^12+45696*x^13+ 40167*x^14+31828*x^15+22603*x^16+14268*x^17+7899*x^18+3762*x^19+ 1498*x^20+474*x^21+110*x^22+16*x^23+x^24).

Mathematica

CoefficientList[Series[(1 + 4*x + 50*x^2 + 262*x^3 + 930*x^4 + 2566*x^5 + 5795*x^6 + 11156*x^7 + 18699*x^8 + 27712*x^9 + 36699*x^10 + 43696*x^11 + 46988*x^12 + 45696*x^13 + 40167*x^14 + 31828*x^15 + 22603*x^16 + 14268*x^17 + 7899*x^18 + 3762*x^19 + 1498*x^20 + 474*x^21 + 110*x^22 + 16*x^23 + x^24)/((1 - x)^2*(1 - x^2)^2*(1 - x^3)^2*(1 - x^4)^2*(1 - x^5)^2), {x, 0, 50}], x] (* G. C. Greubel, Oct 16 2017 *)

Prog

(PARI) {a(n)=polcoeff(truncate(Ser([1, 4, 50, 262, 930, 2566, 5795, 11156, 18699, 27712, 36699, 43696, 46988, 45696, 40167, 31828, 22603, 14268, 7899, 3762, 1498, 474, 110, 16, 1])) /((1-x)^2*(1-x^2)^2*(1-x^3)^2*(1-x^4)^2*(1-x^5)^2 +x*O(x^n)), n)}

Crossrefs

Cf. A123610 (triangle); columns: A005997, A123613, A123614, A123616.

Sequence in context: A184447 A053700 A296393 * A245754 A267248 A053535

Adjacent sequences: A123612 A123613 A123614 * A123616 A123617 A123618

Keyword

nonn

Author

Paul D. Hanna, Oct 03 2006

Status

approved