A162736 G.f. is the polynomial (Product_{k=1..30} (1 - x^(3*k)))/(1-x)^30.

1, 30, 465, 4959, 40890, 277791, 1618199, 8306730, 38329299, 161383520, 627356796, 2272915164, 7734020120, 24874638204, 76028550900, 221849950497, 620471946324, 1669004265525, 4330837858674, 10869702783150, 26449453637412

Offset: 0

Author

N. J. A. Sloane, Dec 02 2009

Keywords

• nonn

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..1365 (terms 0..1000 from Harvey P. Dale)

Programs

Magma

m:=50; R:=PowerSeriesRing(Integers(), m); F:=(&*[(1-x^(3*k)): k in [1..30]])/(1-x)^30; Coefficients(R!(F)); // G. C. Greubel, Jul 07 2018

Mathematica

CoefficientList[Series[Times@@(1-x^Range[3,90,3])/(1-x)^30,{x,0,20}],x] (* Harvey P. Dale, Oct 04 2011 *)

PARI

x='x+O('x^50); A = prod(k=1, 30, (1-x^(3*k)))/(1-x)^30; Vec(A) \\ G. C. Greubel, Jul 07 2018