A116213 (2^(2^(2^n))-1)/(2^(2^n)+1).

1, 3, 3855, 450552876409790643671482431940419874915447411150352389258589821042463539455

Offset: 0

Author

Alexander Adamchuk, Apr 08 2007

Keywords

• nonn

Comments

2^n+1 divides 2^(2^n)-1 iff n is a power of 2.

Crossrefs

Cf. A000215 = Fermat numbers: 2^(2^n)+1. Cf. A051179 = 2^(2^n)-1.

Programs

Mathematica

Table[ (2^2^2^n - 1) / (2^2^n + 1), {n,0,3} ]

Formula

a(n) = (2^(2^(2^n))-1)/(2^(2^n)+1). a(n) = A051179(2^n)/A000215(n).