OFFSET
0,5
LINKS
Index entries for linear recurrences with constant coefficients, signature (1,0,0,2,0,0,0,-1).
FORMULA
G.f.: 1 / (1 - x^4 - x/(1 - x^4)).
a(n) = a(n-1) + 2*a(n-4) - a(n-8) for n > 7.
PROG
(PARI) a(n) = sum(k=0, n\4, binomial(2*n-7*k, k));
CROSSREFS
KEYWORD
nonn,easy
AUTHOR
Seiichi Manyama, Jun 12 2024
STATUS
approved