a(0) = 1; a(n) = Sum_{k=0..n-1} binomial(n,k)^2 * 2^(n-k-1) * a(k).

A340886

a(0) = 1; a(n) = Sum_{k=0..n-1} binomial(n,k)^2 * 2^(n-k-1) * a(k).

Terms

    a(0) =1a(1) =1a(2) =6a(3) =76a(4) =1720a(5) =60816a(6) =3096384a(7) =214579296a(8) =19422473088

External references