A162726 G.f. is the polynomial (Product_{k=1..27} (1 - x^(3*k)))/(1-x)^27.

1, 27, 378, 3653, 27378, 169533, 902537, 4244616, 17985915, 69697614, 249887403, 836666037, 2635961496, 7863966540, 22333781484, 60654192289, 158133109329, 397109727144, 963390950574, 2263730057379, 5163854598459, 11458797521755

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..1107

Maple

m:=27: seq(coeff(series(mul((1-x^(3*k)), k=1..m)/(1-x)^m, x, n+1), x, n), n=0..21); # Muniru A Asiru, Jul 08 2018

Mathematica

With[{num=Times@@(1-x^(3*Range[27]))}, CoefficientList[Series[num/(1-x)^27, {x, 0, 30}], x]] Harvey P. Dale, May 20 2012

Prog

(PARI) x='x+O('x^50); A = prod(k=1, 27, (1-x^(3*k)))/(1-x)^27; Vec(A) \\ G. C. Greubel, Jul 06 2018
(Magma) m:=50; R<x>:=PowerSeriesRing(Integers(), m); F:=(&*[(1-x^(3*k)): k in [1..27]])/(1-x)^27; Coefficients(R!(F)); // G. C. Greubel, Jul 06 2018

Crossrefs

Sequence in context: A162369 A231858 A341564 * A010979 A022591 A321954

Adjacent sequences: A162723 A162724 A162725 * A162727 A162728 A162729

Keyword

nonn

Author

N. J. A. Sloane, Dec 02 2009

Status

approved