OFFSET
1,2
LINKS
Andrew Howroyd, Table of n, a(n) for n = 1..500
Index entries for linear recurrences with constant coefficients, signature (66,-1083,6508,-13671,11826,-3645).
FORMULA
a(n) = 45^n - (8*n + 1)*9^n + 4*n*(8*n + 1). - Andrew Howroyd, May 06 2020
From Colin Barker, Jul 19 2020: (Start)
G.f.: 16*x^2*(49 + 1341*x - 6093*x^2 - 6561*x^3) / ((1 - x)^3*(1 - 9*x)^2*(1 - 45*x)).
a(n) = 66*a(n-1) - 1083*a(n-2) + 6508*a(n-3) - 13671*a(n-4) + 11826*a(n-5) - 3645*a(n-6) for n>6.
(End)
PROG
(PARI) a(n) = {45^n - (8*n + 1)*9^n + 4*n*(8*n + 1)} \\ Andrew Howroyd, May 06 2020
(PARI) concat(0, Vec(16*x^2*(49 + 1341*x - 6093*x^2 - 6561*x^3) / ((1 - x)^3*(1 - 9*x)^2*(1 - 45*x)) + O(x^40))) \\ Colin Barker, Jul 19 2020
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
R. H. Hardin, May 29 2009
EXTENSIONS
Terms a(7) and beyond from Andrew Howroyd, May 06 2020
STATUS
approved