[go: up one dir, main page]

login
A016281
Expansion of 1/((1-2x)(1-3x)(1-12x)).
1
1, 17, 223, 2741, 33103, 397901, 4776871, 57328757, 687964255, 8255629085, 99067724119, 1188813216773, 14265760187407, 171189127015469, 2054269538501767, 24651234505002389, 295814814189037759
OFFSET
0,2
FORMULA
a(n) = (2/5)*2^(n-1) - 3^(n-1) + (8/5)*12^(n-1). - Antonio Alberto Olivares, Feb 06 2010
a(n) = 17*a(n-1) - 66*a(n-2) + 72*a(n-3). - Vincenzo Librandi, Jun 25 2013
MATHEMATICA
CoefficientList[Series[1 / ((1 - 2 x) (1 - 3 x) (1 - 12 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Jun 25 2013 *)
PROG
(Magma) m:=20; R<x>:=PowerSeriesRing(Integers(), m); Coefficients(R!(1/((1-2*x)*(1-3*x)*(1-12*x)))); /* or */I:=[1, 17, 223]; [n le 3 select I[n] else 17*Self(n-1)-66*Self(n-2)+72*Self(n-3): n in [1..20]]; // Vincenzo Librandi, Jun 25 2013
CROSSREFS
Sequence in context: A285233 A063043 A016174 * A160398 A181380 A081044
KEYWORD
nonn,easy
STATUS
approved