a(n) = Sum_{k=0..n} abs(Stirling1(n+1,k+1))*Stirling2(n+1,k+1)*k!.

A192563

a(n) = Sum_{k=0..n} abs(Stirling1(n+1,k+1))*Stirling2(n+1,k+1)*k!.

Terms

    a(0) =1a(1) =2a(2) =13a(3) =161a(4) =3148a(5) =87784a(6) =3274640a(7) =156359874a(8) =9252910816a(9) =662065322016

External references