a(n) = Sum_{k=0..n} (-1)^(n-k) C(n,k)*C(k^2,n).
A003235
a(n) = Sum_{k=0..n} (-1)^(n-k) C(n,k)*C(k^2,n).
Terms
- a(0) =1a(1) =1a(2) =6a(3) =72a(4) =1322a(5) =32550a(6) =1003632a(7) =37162384a(8) =1605962556a(9) =79330914540
External references
- oeis: A003235