a(0)=0, a(1)=1; for n >= 1, a(n+1) = (n+2)*a(n) + 2*Sum_{k=2..n-1} binomial(n, k)*a(k)*a(n-k+1).
A119649
a(0)=0, a(1)=1; for n >= 1, a(n+1) = (n+2)*a(n) + 2*Sum_{k=2..n-1} binomial(n, k)*a(k)*a(n-k+1).
Terms
- a(0) =0a(1) =1a(2) =3a(3) =12a(4) =114a(5) =1404a(6) =22968a(7) =456408a(8) =10762992a(9) =292851648a(10) =9038285280a(11) =311858347968
External references
- oeis: A119649