A162505 G.f. is the polynomial (1-x^3) * (1-x^6) * (1-x^9) * (1-x^12) / (1-x)^4.

1, 4, 10, 19, 31, 46, 63, 81, 99, 116, 131, 143, 151, 154, 151, 143, 131, 116, 99, 81, 63, 46, 31, 19, 10, 4, 1

Offset

0,2

Comments

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

Links

Table of n, a(n) for n=0..26.

Formula

Euler transform of period 12 sequence [4, 0, -1, 0, 0, -1, 0, 0, -1, 0, 0, -1]. - Michael Somos, Aug 02 2018

Maple

m:=4: seq(coeff(series(mul((1-x^(3*k)), k=1..m)/(1-x)^m, x, n+1), x, n), n=0..26); # Muniru A Asiru, Jul 07 2018

Mathematica

CoefficientList[ Series[Times @@ (1 - x^(3*Range@4))/(1 - x)^4, {x, 0, 40}], x] (* Harvey P. Dale, Feb 05 2012 and slightly modified by Robert G. Wilson v, Jul 23 2018 *)

Prog

(PARI) x='x+O('x^27); Vec((1-x^3)*(1-x^6)*(1-x^9)*(1-x^12)/(1-x)^4) \\ G. C. Greubel, Jul 06 2018
(Magma) m:=27; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!((1-x^3)*(1-x^6)*(1-x^9)*(1-x^12)/(1-x)^4)); // G. C. Greubel, Jul 06 2018

Crossrefs

Sequence in context: A301248 A160425 A152946 * A025720 A022793 A005448

Adjacent sequences: A162502 A162503 A162504 * A162506 A162507 A162508

Keyword

nonn,fini,full

Author

N. J. A. Sloane, Dec 02 2009

Status

approved