OFFSET
1,5
COMMENTS
Lim_{n->infinity} a(n)/a(n-1) = 1.29064880134670962239...
LINKS
Index entries for linear recurrences with constant coefficients, signature (1,-1,1,1).
FORMULA
G.f.: x*(1 + x^2)/(1 - x + x^2 - x^3 - x^4). - Andrew Howroyd, May 02 2021
PROG
(PARI) Vec((1 + x^2)/(1 - x + x^2 - x^3 - x^4) + O(x^50)) \\ Andrew Howroyd, May 02 2021
(PARI) my(p=Mod('x, 'x^4-'x^3+'x^2-'x-1)); a(n) = vecsum(Vec(lift(p^(n-1)))); \\ Kevin Ryde, May 02 2021
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Zachary Gaiski, May 02 2021
STATUS
approved