A162002 Numbers n for which 2^^n == 2^2^n (mod n); for the "^^" notation see A092188.

1, 2, 3, 4, 5, 6, 8, 10, 12, 14, 15, 16, 17, 18, 20, 24, 26, 28, 30, 32, 34, 36, 40, 42, 43, 44, 46, 48, 51, 52, 56, 58, 60, 64, 68, 70, 72, 76, 78, 80, 84, 85, 88, 90, 96, 100, 102, 104, 112, 120, 124, 126, 127, 128, 130, 132, 136, 140, 141, 144, 145, 148, 156, 160, 164

Offset

1,2

Links

Table of n, a(n) for n=1..65.

Robert Munafo, 2^^N == 2^(2^N) mod N

Example

3 is in the sequence because 2^2^3 = 2^8 = 256 == 1 mod 3, and 2^^3 = 2^2^2 = 2^4 = 16 == 1 mod 3.

Crossrefs

Cf. A092188, A162018, A014221

Sequence in context: A173643 A120722 A090811 * A182764 A045880 A273011

Adjacent sequences: A161999 A162000 A162001 * A162003 A162004 A162005

Keyword

easy,nonn

Author

Robert Munafo, Jun 24 2009

Status

approved