a(n) = a(n-1)^2 - 1, a(0) = 2.

A003096

a(n) = a(n-1)^2 - 1, a(0) = 2.

Terms

    a(0) =2a(1) =3a(2) =8a(3) =63a(4) =3968a(5) =15745023

External references