A180060 a(n) = 2^(2^n mod n) mod n.

0, 1, 1, 1, 4, 4, 4, 1, 4, 6, 4, 4, 4, 2, 1, 1, 4, 16, 4, 16, 4, 16, 4, 16, 3, 16, 13, 16, 4, 16, 4, 1, 25, 16, 29, 16, 4, 16, 22, 16, 4, 16, 4, 20, 32, 16, 4, 16, 22, 16, 1, 16, 4, 52, 8, 32, 28, 16, 4, 16, 4, 16, 4, 1, 61, 16, 4, 52, 49, 46, 4, 16, 4, 16, 31, 24, 36, 16, 4, 16

Offset: 1

Author

Juri-Stepan Gerasimov, Jan 14 2011

Keywords

• nonn

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Crossrefs

Cf. A000079, A179976.

Programs

Mathematica

Table[Mod[2^(Mod[2^n, n]), n], {n, 50}] (* Alonso del Arte, Jan 14 2011 *)
Table[PowerMod[2,PowerMod[2,n,n],n],{n,80}] (* Harvey P. Dale, Oct 09 2019 *)

Formula

a(n) = 2^A015910(n) mod n.

Extensions

Entries corrected by R. J. Mathar, Jan 14 2011