a(0)=a(1)=1; thereafter a(n+1) = 1 + a(n) + Sum_{m=1..n} binomial(2*n, 2*m-1)*a(n+1-m).
A308008
a(0)=a(1)=1; thereafter a(n+1) = 1 + a(n) + Sum_{m=1..n} binomial(2*n, 2*m-1)*a(n+1-m).
Terms
- a(0) =1a(1) =1a(2) =4a(3) =25a(4) =262a(5) =3991a(6) =82132a(7) =2173933a(8) =71445730a(9) =2839498243a(10) =133692806800
External references
- oeis: A308008