A178427 7 followed by the Fermat numbers A152581.

7, 9, 65, 4097, 16777217, 281474976710657, 79228162514264337593543950337, 6277101735386680763835789423207666416102355444464034512897

Offset: 0

Author

Roger L. Bagula, May 27 2010

Keywords

• nonn
• less

Comments

If a(0)=3, the recursion formula gives A000215.

Crossrefs

Cf. A000215, A152581, A178426, A178428.

Programs

Mathematica

a[0] := 7;
a[n_] := a[n] = Product[a[i], {i, 0, n - 1}] + 2;
Table[a[n], {n, 0, 10}]

Formula

a(0)=7. a(n) = 2 + Product_{i=0..n-1} a(i).

Extensions

Definition simplified by the Assoc. Eds. of the OEIS - May 28 2010

Incorrect a(8) removed by Georg Fischer, May 22 2024