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A021824 Expansion of 1/((1-x)(1-4x)(1-6x)(1-9x)). 1
1, 20, 267, 3010, 31073, 304920, 2901319, 27075950, 249555405, 2281579300, 20749095731, 188036746170, 1700122392697, 15347941075760, 138412864844703, 1247405586235270, 11236794818538149, 101192043527859900 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Vincenzo Librandi, Table of n, a(n) for n = 0..200

FORMULA

a(n) = (9^(n+3) - 4*6^(n+3) + 4^(n+4) - 1)/120. [Yahia Kahloune, Jul 05 2013]

MATHEMATICA

CoefficientList[Series[1 / ((1 - x) (1 - 4 x) (1 - 6 x) (1 - 9 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Jul 11 2013 *)

CROSSREFS

Sequence in context: A021854 A025939 A278773 * A125455 A019928 A025934

Adjacent sequences:  A021821 A021822 A021823 * A021825 A021826 A021827

KEYWORD

nonn,easy

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified April 22 06:14 EDT 2019. Contains 322329 sequences. (Running on oeis4.)