A162635 G.f. is the polynomial (1-x^3) * (1-x^6) * (1-x^9) * (1-x^12) * (1-x^15) * (1-x^18) * (1-x^21) * (1-x^24) * (1-x^27) * (1-x^30) * (1-x^33) * (1-x^36) * (1-x^39) * (1-x^42) * (1-x^45) / (1-x)^15.

1, 15, 120, 679, 3045, 11508, 38079, 113205, 308022, 777750, 1841916, 4126002, 8801750, 17980764, 35339430, 67083871, 123403134, 220608645, 384219820, 653331285, 1086688143, 1771003801, 2832181620, 4450248525, 6878976970

Offset

0,2

Comments

This is a row of the triangle in A162499. Only finitely many terms are nonzero.

Links

G. C. Greubel, Table of n, a(n) for n = 0..345

Maple

P:= normal((1-x^3) * (1-x^6) * (1-x^9) * (1-x^12) * (1-x^15) * (1-x^18) * (1-x^21) * (1-x^24) * (1-x^27) * (1-x^30) * (1-x^33) * (1-x^36) * (1-x^39) * (1-x^42) * (1-x^45) / (1-x)^15):
seq(coeff(P, x, n), n=0..degree(P)); # Robert Israel, Jul 06 2018

Mathematica

CoefficientList[Series[Times@@(1-x^(3*Range[15]))/(1-x)^15, {x, 0, 50}], x] (* G. C. Greubel, Jul 06 2018 *)

Prog

(PARI) x='x+O('x^50); A = prod(k=1, 15, (1-x^(3*k)))/(1-x)^15; Vec(A) \\ G. C. Greubel, Jul 06 2018
(Magma) m:=50; R<x>:=PowerSeriesRing(Integers(), m); F:=(&*[(1-x^(3*k)): k in [1..15]])/(1-x)^15; Coefficients(R!(F)); // G. C. Greubel, Jul 06 2018

Crossrefs

Sequence in context: A185542 A226989 A126898 * A247612 A010967 A022580

Adjacent sequences: A162632 A162633 A162634 * A162636 A162637 A162638

Keyword

nonn,fini,full

Author

N. J. A. Sloane, Dec 02 2009

Status

approved