a(n) = Sum_{k=0..n} abs(Stirling1(n,k))*Stirling2(n,k)*(k!)^2.

A192564

a(n) = Sum_{k=0..n} abs(Stirling1(n,k))*Stirling2(n,k)*(k!)^2.

Terms

    a(0) =1a(1) =1a(2) =5a(3) =74a(4) =2186a(5) =106524a(6) =7703896a(7) =773034912a(8) =102673179360

External references