a(n) = Product{k=1 to n} sigma_{n-k+1}(k), where sigma_m(k) = sum{j|k} j^m.
A108699
a(n) = Product{k=1 to n} sigma_{n-k+1}(k), where sigma_m(k) = sum{j|k} j^m.
Terms
- a(0) =1a(1) =3a(2) =20a(3) =630a(4) =59976a(5) =61631856a(6) =218220912000
External references
- oeis: A108699