a(0) = 1; a(n) = (1/n) * Sum_{k=1..n} binomial(n,k)^2 * k * 4^(k-1) * a(n-k).

A337594

a(0) = 1; a(n) = (1/n) * Sum_{k=1..n} binomial(n,k)^2 * k * 4^(k-1) * a(n-k).

Terms

    a(0) =1a(1) =1a(2) =6a(3) =58a(4) =920a(5) =21176a(6) =654960a(7) =26114768a(8) =1298070912a(9) =78359732608

External references