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%I #14 Sep 08 2022 08:44:45
%S 1,26,473,7462,109221,1527162,20707681,274691534,3584491901,
%T 46184032258,589079813049,7452543446166,93649963947541,
%U 1170213435915914,14553113785023377,180253443514702558
%N Expansion of 1/((1-x)(1-2x)(1-11x)(1-12x)).
%H Vincenzo Librandi, <a href="/A021334/b021334.txt">Table of n, a(n) for n = 0..200</a>
%H <a href="/index/Rec">Index entries for linear recurrences with constant coefficients</a>, signature (26,-203,442,-264).
%F a(n) = (9*12^(n+3) - 11^(n+4) + 11*2^(n+3) - 9)/990. [_Yahia Kahloune_, Jul 07 2013]
%F a(0)=1, a(1)=26; for n>1, a(n) = 23*a(n-1) -132*a(n-2) +2^n -1. - _Vincenzo Librandi_, Jul 09 2013
%F a(0)=1, a(1)=26, a(2)=473, a(3)=7462; for n>3, a(n) = 26*a(n-1) -203*a(n-2) +442*a(n-3) -264*a(n-4). - _Vincenzo Librandi_, Jul 09 2013
%t CoefficientList[Series[1 / ((1 - x) (1 - 2 x) (1 - 11 x) (1 - 12 x)), {x, 0, 20}], x] (* _Vincenzo Librandi_, Jul 09 2013 *)
%o (Magma) m:=25; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-x)*(1-2*x)*(1-11*x)*(1-12*x)))); /* or */ I:=[1, 26, 473, 7462]; [n le 4 select I[n] else 26*Self(n-1)-203*Self(n-2)+442*Self(n-3)-264*Self(n-4): n in [1..25]]; // _Vincenzo Librandi_, Jul 09 2013
%K nonn,easy
%O 0,2
%A _N. J. A. Sloane_.
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