a(n) = sum(abs(stirling1(n+1,k+1))*stirling2(n,k),k=0..n).

A192549

a(n) = sum(abs(stirling1(n+1,k+1))*stirling2(n,k),k=0..n).

Terms

    a(0) =1a(1) =1a(2) =4a(3) =30a(4) =356a(5) =5925a(6) =129949a(7) =3609522a(8) =123202470a(9) =5047071210a(10) =243591826248

External references