a(n) = Sum_{k=1..n} ((k-1)!)^2*Stirling2(n,k)^2.
A048163
a(n) = Sum_{k=1..n} ((k-1)!)^2*Stirling2(n,k)^2.
Terms
- a(0) =1a(1) =2a(2) =14a(3) =230a(4) =6902a(5) =329462a(6) =22934774a(7) =2193664790a(8) =276054834902
External references
- oeis: A048163
A048163
a(n) = Sum_{k=1..n} ((k-1)!)^2*Stirling2(n,k)^2.