A000142 (n+1) * A002109(n), a product of factorials and hyperfactorials.

A240993

A000142 (n+1) * A002109(n), a product of factorials and hyperfactorials.

Terms

    a(0) =1a(1) =2a(2) =24a(3) =2592a(4) =3317760a(5) =62208000000

External references