A178426 11 followed by the Fermat numbers A152585.

11, 13, 145, 20737, 429981697, 184884258895036417, 34182189187166852111368841966125057, 1168422057627266461843148138873451659428421700563161428957815831003137

Offset

0,1

Comments

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

Links

Table of n, a(n) for n=0..7.

Formula

a(0) = 11. a(n)= 2 + Product_{i=0..n-1} a(i).

Product_{n>=0} (1 - 1/a(n)) = 5/6. - Amiram Eldar, Dec 01 2025

Mathematica

a[0] := 11;
a[n_] := a[n] = Product[a[i], {i, 0, n - 1}] + 2;
Table[a[n], {n, 0, 10}]

Crossrefs

Cf. A000215, A152585, A178427, A178428.

Sequence in context: A108090 A136296 A094621 * A252170 A366718 A144375

Adjacent sequences: A178423 A178424 A178425 * A178427 A178428 A178429

Keyword

nonn,less

Author

Roger L. Bagula, May 27 2010

Extensions

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

Status

approved