OFFSET
1,2
LINKS
Andrew Howroyd, Table of n, a(n) for n = 1..500
Index entries for linear recurrences with constant coefficients, signature (19,-115,241,-208,64).
FORMULA
a(n) = n*((7/2)*8^n - 49*n) for n > 1. - Andrew Howroyd, May 04 2020
From Colin Barker, Jul 16 2020: (Start)
G.f.: 7*x^2*(36 + 21*x - 1175*x^2 + 624*x^3 - 192*x^4) / ((1 - x)^3*(1 - 8*x)^2).
a(n) = 19*a(n-1) - 115*a(n-2) + 241*a(n-3) - 208*a(n-4) + 64*a(n-5) for n>6.
(End)
PROG
(PARI) a(n) = if(n <= 1, 0, n*(7*8^n/2 - 49*n)) \\ Andrew Howroyd, May 04 2020
(PARI) concat(0, Vec(7*x^2*(36 + 21*x - 1175*x^2 + 624*x^3 - 192*x^4) / ((1 - x)^3*(1 - 8*x)^2) + O(x^20))) \\ Colin Barker, Jul 16 2020
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
R. H. Hardin, May 21 2009
EXTENSIONS
Terms a(7) and beyond from Andrew Howroyd, May 04 2020
STATUS
approved