a(n) = Sum_{k=0..n} k! * 2^k * k^n * Stirling1(n,k).

A350719

a(n) = Sum_{k=0..n} k! * 2^k * k^n * Stirling1(n,k).

Terms

    a(0) =1a(1) =2a(2) =30a(3) =1108a(4) =76372a(5) =8463328a(6) =1375868768a(7) =308440047648

External references