OFFSET
0,2
FORMULA
G.f.: exp( Sum_{k>=1} A378460(k) * x^k/k ).
a(n) = (1/(n+1)) * [x^n] 1/(1 - x - x/(1 - x))^(n+1).
a(n) = (1/(n+1)) * Sum_{k=0..n} binomial(n+k,k) * binomial(2*n+k,n-k).
a(n) ~ ((16 + 12*2^(1/3) + 9*2^(2/3))/5)^n / (sqrt(6*(4 - 3*2^(1/3))*Pi) * n^(3/2)). - Vaclav Kotesovec, Nov 27 2024
PROG
(PARI) my(N=30, x='x+O('x^N)); Vec(serreverse(x*(1-x-x/(1-x)))/x)
(PARI) a(n) = sum(k=0, n, binomial(n+k, k)*binomial(2*n+k, n-k))/(n+1);
CROSSREFS
KEYWORD
nonn
AUTHOR
Seiichi Manyama, Nov 27 2024
STATUS
approved