G.f.: exp( Sum_{n>=1} A206152(n)*x^n/n ), where A206152(n) = Sum_{k=0..n} binomial(n,k)^(n+k).

A206151

G.f.: exp( Sum_{n>=1} A206152(n)*x^n/n ), where A206152(n) = Sum_{k=0..n} binomial(n,k)^(n+k).

Terms

    a(0) =1a(1) =2a(2) =7a(3) =120a(4) =16257a(5) =22426576a(6) =181974299842

External references