OFFSET
0,3
FORMULA
a(n) = Sum_{k=0..n} 8^k * binomial((n+3*k)/4-1,k).
PROG
(PARI) a(n) = sum(k=0, n, 8^k*binomial((n+3*k)/4-1, k));
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Jun 07 2024
STATUS
approved