OFFSET
0,10
FORMULA
a(n) = Sum_{k=0..floor(n/4)} binomial(k,n-4*k)^2.
PROG
(PARI) my(N=60, x='x+O('x^N)); Vec(1/sqrt((1-x^4-x^5)^2-4*x^9))
(PARI) a(n) = sum(k=0, n\4, binomial(k, n-4*k)^2);
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Oct 02 2024
STATUS
approved