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A021824 Expansion of 1/((1-x)(1-4x)(1-6x)(1-9x)). 1

%I

%S 1,20,267,3010,31073,304920,2901319,27075950,249555405,2281579300,

%T 20749095731,188036746170,1700122392697,15347941075760,

%U 138412864844703,1247405586235270,11236794818538149,101192043527859900

%N Expansion of 1/((1-x)(1-4x)(1-6x)(1-9x)).

%H Vincenzo Librandi, <a href="/A021824/b021824.txt">Table of n, a(n) for n = 0..200</a>

%F a(n) = (9^(n+3) - 4*6^(n+3) + 4^(n+4) - 1)/120. [_Yahia Kahloune_, Jul 05 2013]

%t CoefficientList[Series[1 / ((1 - x) (1 - 4 x) (1 - 6 x) (1 - 9 x)), {x, 0, 20}], x] (* _Vincenzo Librandi_, Jul 11 2013 *)

%K nonn,easy

%O 0,2

%A _N. J. A. Sloane_.

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Last modified January 20 16:32 EST 2022. Contains 350472 sequences. (Running on oeis4.)