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

A205815

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

Terms

    a(0) =1a(1) =17a(2) =136a(3) =1585a(4) =16986a(5) =282338a(6) =4784900a(7) =101750689a(8) =2359918963a(9) =62200943002

External references