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

A340888

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

Terms

    a(0) =1a(1) =1a(2) =8a(3) =124a(4) =3456a(5) =150656a(6) =9453056a(7) =807373568a(8) =90066059264

External references