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

A135748

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

Terms

    a(0) =1a(1) =3a(2) =21a(3) =567a(4) =67689a(5) =33887403a(6) =68921796861

External references