OFFSET
0,4
FORMULA
G.f.: (1-x^3-x^4)/((1-x^3-x^4)^2 - 4*x^7)^(3/2).
PROG
(PARI) a(n) = sum(k=0, n\3, (k+1)*binomial(k, n-3*k)^2);
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Oct 17 2024
STATUS
approved