a(n) = Sum_{k=0..n} binomial(n,k)^2 * Stirling2(2*k,k) * Stirling2(2*n-2*k,n-k).
A384471
a(n) = Sum_{k=0..n} binomial(n,k)^2 * Stirling2(2*k,k) * Stirling2(2*n-2*k,n-k).
Terms
- a(0) =1a(1) =2a(2) =18a(3) =306a(4) =8046a(5) =296100a(6) =14307254a(7) =865996306a(8) =63308257198
External references
- oeis: A384471