Convolution of n! and n^n.

Terms

a(0) =1a(1) =2a(2) =7a(3) =39a(4) =321a(5) =3603a(6) =51391a(7) =884873a(8) =17770445a(9) =406673247a(10) =10431884283a(11) =296262164637