OFFSET
5,1
LINKS
Colin Barker, Table of n, a(n) for n = 5..1000
Index entries for linear recurrences with constant coefficients, signature (22,-216,1248,-4710,12180,-22004,27752,-23937,13446,-4428,648).
FORMULA
G.f.: 2*x^5*(5 - 36*x + 82*x^2 - 36*x^3 - 87*x^4 + 80*x^5) / ((1 - x)^4*(1 - 2*x)^3*(1 - 3*x)^4).
a(n) = (n*(27 + 81*2^n - 115*3^n + 3*(27*2^n+2*3^n)*n + (-27+3^n)*n^2)) / 162. - Colin Barker, May 03 2019
PROG
(PARI) Vec(2*x^5*(5 - 36*x + 82*x^2 - 36*x^3 - 87*x^4 + 80*x^5) / ((1 - x)^4*(1 - 2*x)^3*(1 - 3*x)^4) + O(x^30)) \\ Colin Barker, Nov 03 2017
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Mike Zabrocki, Nov 10 2004
STATUS
approved