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

A192559

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

Terms

    a(0) =1a(1) =1a(2) =3a(3) =28a(4) =518a(5) =15446a(6) =669422a(7) =39529008a(8) =3040944216a(9) =294858211992

External references