|
|
A021334
|
|
Expansion of 1/((1-x)(1-2x)(1-11x)(1-12x)).
|
|
1
|
|
|
1, 26, 473, 7462, 109221, 1527162, 20707681, 274691534, 3584491901, 46184032258, 589079813049, 7452543446166, 93649963947541, 1170213435915914, 14553113785023377, 180253443514702558
(list;
graph;
refs;
listen;
history;
text;
internal format)
|
|
|
OFFSET
|
0,2
|
|
LINKS
|
|
|
FORMULA
|
a(n) = (9*12^(n+3) - 11^(n+4) + 11*2^(n+3) - 9)/990. [Yahia Kahloune, Jul 07 2013]
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
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
|
|
MATHEMATICA
|
CoefficientList[Series[1 / ((1 - x) (1 - 2 x) (1 - 11 x) (1 - 12 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Jul 09 2013 *)
|
|
PROG
|
(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
|
|
CROSSREFS
|
|
|
KEYWORD
|
nonn,easy
|
|
AUTHOR
|
|
|
STATUS
|
approved
|
|
|
|