a(n) = Sum_{k=0..n} k! * (k+1)! * Stirling1(n+1,k+1)^2.

A382827

a(n) = Sum_{k=0..n} k! * (k+1)! * Stirling1(n+1,k+1)^2.

Terms

    a(0) =1a(1) =3a(2) =34a(3) =854a(4) =37556a(5) =2546852a(6) =246113904a(7) =32104625520

External references