47326

Appears in sequences

• Triangle read by rows: T(n,0)=1, T(n,n)=(2*n-1)!!+1, T(n,k) = 2*(n-k) * T(n-1,k-1) + 2*(k+1)*T(n-1,k).at n=37A099755
• Number of length n+6 0..1 arrays with at most two downsteps in every n consecutive neighbor pairs.at n=13A256821