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URL: https://oeis.org/A021104

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A021104
Expansion of g.f. 1/((1 - x)*(1 - 2*x)*(1 - 4*x)*(1 - 12*x)).
1
1, 19, 263, 3311, 40383, 487263, 5857951, 70338847, 844240415, 10131583007, 121581790239, 1458992663583, 17507956694047, 210095659269151, 2521148627024927, 30253786387545119, 363045448103656479, 4356545423056600095, 52278545259930614815, 627342543852174081055, 7528110529158117882911
OFFSET
0,2
FORMULA
a(n) = -(1/33) + (2/5)*2^n - (4/3)*4^n + (108/55)*12^n. - Antonio Alberto Olivares, May 22 2012
a(0)=1, a(1)=19; for n>1, a(n) = 16*a(n-1) -48*a(n-2)+2^n-1. - Vincenzo Librandi, Jul 07 2013
a(0)=1, a(1)=19, a(2)=263, a(3)=3311; for n>3, a(n) = 19*a(n-1) -98*a(n-2) +176*a(n-3) -96*a(n-4). - Vincenzo Librandi, Jul 07 2013
MATHEMATICA
CoefficientList[Series[1 / ((1 - x) (1 - 2 x) (1 - 4 x) (1 - 12 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Jul 07 2013 *)
LinearRecurrence[{19, -98, 176, -96}, {1, 19, 263, 3311}, 30] (* Harvey P. Dale, Jul 31 2018 *)
PROG
(Magma) m:=25; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-x)*(1-2*x)*(1-4*x)*(1-12*x)))); // Vincenzo Librandi, Jul 07 2013
(Magma) I:=[1, 19, 263, 3311]; [n le 4 select I[n] else 19*Self(n-1)-98*Self(n-2)+176*Self(n-3)-96*Self(n-4): n in [1..25]]; // Vincenzo Librandi, Jul 07 2013
CROSSREFS
Sequence in context: A142817 A294828 A016257 * A209075 A017161 A036736
KEYWORD
nonn,easy
STATUS
approved