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A023947
Expansion of 1/((1-x)(1-5x)(1-10x)(1-12x)).
1
1, 28, 527, 8390, 122121, 1683768, 22407907, 291019450, 3713967341, 46787388908, 583658682087, 7226065372110, 88934701511761, 1089437114484448, 13295459966641067, 161767703674942370
OFFSET
0,2
FORMULA
a(n) = (90*12^(n+3) - 154*10^(n+3) + 99*5^(n+3) - 35)/13860. [Yahia Kahloune, Jun 27 2013]
a(0)=1, a(1)=28, a(2)=527, a(3)=8390; for n>3, a(n) = 28*a(n-1) -257*a(n-2) +830*a(n-3) -600*a(n-4). - Vincenzo Librandi, Jul 12 2013
MATHEMATICA
CoefficientList[Series[1 / ((1 - x) (1 - 5 x) (1 - 10 x) (1 - 12 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Jul 12 2013 *)
PROG
(Magma) I:=[1, 28, 527, 8390]; [n le 4 select I[n] else 28*Self(n-1)-257*Self(n-2)+830*Self(n-3)-600*Self(n-4): n in [1..25]]; /* or */ m:=25; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-x)*(1-5*x)*(1-10*x)*(1-12*x)))); // Vincenzo Librandi, Jul 12 2013
CROSSREFS
Sequence in context: A025984 A020977 A020973 * A020972 A025957 A020758
KEYWORD
nonn,easy
AUTHOR
STATUS
approved