OFFSET
0,3
FORMULA
a(n) = [x^n] 1/((1-x-x^2) * (1-x)^(n-1)).
a(n) ~ 4^n / sqrt(Pi*n). - Vaclav Kotesovec, Apr 16 2024
a(n) = A354267(2*n, n). - Peter Luschny, Apr 25 2024
PROG
(PARI) a(n) = sum(k=0, n\2, binomial(2*n-k-1, n-2*k));
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Apr 10 2024
STATUS
approved