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A162539 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)^6. 1
1, 6, 21, 55, 120, 231, 405, 660, 1014, 1484, 2085, 2829, 3724, 4773, 5973, 7315, 8784, 10359, 12013, 13713, 15420, 17091, 18681, 20145, 21440, 22527, 23373, 23952, 24246, 24246, 23952, 23373, 22527, 21440, 20145, 18681, 17091, 15420, 13713 (list; graph; refs; listen; history; text; internal format)
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..57

MATHEMATICA

CoefficientList[ Series[Times @@ (1 - x^(3 Range@6))/(1 - x)^6, {x, 0, 70}], x] (* G. C. Greubel, Jul 06 2018 and slightly modified by Robert G. Wilson v, Jul 23 2018 *)

PROG

(PARI) x='x+O('x^58); Vec((1-x^3)*(1-x^6)*(1-x^9)*(1-x^12)*(1-x^15)*(1-x^18)/(1-x)^6) /* complete row */ \\ G. C. Greubel, Jul 06 2018

(MAGMA) m:=58; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!((1-x^3)*(1-x^6)*(1-x^9)*(1-x^12)*(1-x^15)*(1-x^18)/(1-x)^6)); /* complete row */ // G. C. Greubel, Jul 06 2018

CROSSREFS

Sequence in context: A025203 A262719 A238702 * A259474 A002817 A132366

Adjacent sequences:  A162536 A162537 A162538 * A162540 A162541 A162542

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Dec 02 2009

STATUS

approved

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Last modified January 24 16:34 EST 2020. Contains 331207 sequences. (Running on oeis4.)