OFFSET
0,3
LINKS
Harvey P. Dale, Table of n, a(n) for n = 0..1000
Index entries for linear recurrences with constant coefficients, signature (4,2,-12,-9).
FORMULA
a(n) = (1/6)*((n + 3)*3^n + (3*n + 3)*(-1)^n).
O.g.f.: -(x - 1)^3/((-1 + 3*x)^2*(1 + x)^2). - R. J. Mathar, Apr 02 2008
E.g.f.: exp(x)*(cosh(2*x) + x*sinh(2*x)). - Stefano Spezia, Aug 04 2022
MATHEMATICA
LinearRecurrence[{4, 2, -12, -9}, {1, 1, 9, 25}, 30] (* Harvey P. Dale, Feb 07 2023 *)
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Paul Barry, May 02 2003
STATUS
approved