a(n) = a(n-1)*a(n-2)*a(n-3) with a(1)=1, a(2)=2 and a(3)=3.

A000308

a(n) = a(n-1)*a(n-2)*a(n-3) with a(1)=1, a(2)=2 and a(3)=3.

Terms

    a(0) =1a(1) =2a(2) =3a(3) =6a(4) =36a(5) =648a(6) =139968a(7) =3265173504

External references