a(n) = a(n-1)*a(n-2)*a(n-3)*a(n-4); for n < 5, a(n) = n.

A000336

a(n) = a(n-1)*a(n-2)*a(n-3)*a(n-4); for n < 5, a(n) = n.

Terms

    a(0) =1a(1) =2a(2) =3a(3) =4a(4) =24a(5) =576a(6) =165888a(7) =9172942848

External references