a(0)=1, a(n) = n*(a(n-1) + n).

Terms

a(0) =1a(1) =2a(2) =8a(3) =33a(4) =148a(5) =765a(6) =4626a(7) =32431a(8) =259512a(9) =2335689a(10) =23356990a(11) =256927011a(12) =3083124276a(13) =40080615757a(14) =561128620794