a(n) = sum(abs(stirling1(n+1,k+1))*k!^2,k=0..n).

A192551

a(n) = sum(abs(stirling1(n+1,k+1))*k!^2,k=0..n).

Terms

    a(0) =1a(1) =2a(2) =9a(3) =77a(4) =1150a(5) =27394a(6) =957040a(7) =45996880a(8) =2904500048a(9) =232935169536

External references