OFFSET
0,11
FORMULA
a(n) = (-1)^n + Sum_{k=0..floor((n-1)/4)} a(k) * a(n-1-4*k).
PROG
(PARI) a_vector(n) = my(v=vector(n+1)); for(i=0, n, v[i+1]=(-1)^i+sum(j=0, (i-1)\4, v[j+1]*v[i-4*j])); v;
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Nov 27 2023
STATUS
approved