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

A134173

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

Terms

    a(0) =1a(1) =3a(2) =8a(3) =68a(4) =2106a(5) =223776a(6) =80532200a(7) =98945392200

External references