OFFSET
0,2
LINKS
Vincenzo Librandi, Table of n, a(n) for n = 0..200
Index entries for linear recurrences with constant coefficients, signature (20, -133, 330, -216).
FORMULA
G.f.: 1/((1-x)(1-4x)(1-6x)(1-9x)).
a(n) = (9^(n+3) - 4*6^(n+3) + 4^(n+4) - 1)/120. - Yahia Kahloune, Jul 05 2013
MATHEMATICA
CoefficientList[Series[1 / ((1 - x) (1 - 4 x) (1 - 6 x) (1 - 9 x)), {x, 0, 20}], x] (* Vincenzo Librandi, Jul 11 2013 *)
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
STATUS
approved