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A162018 Numbers n for which 2^^n != 2^2^n (mod n); for the "^^" notation see A092188. 1
7, 9, 11, 13, 19, 21, 22, 23, 25, 27, 29, 31, 33, 35, 37, 38, 39, 41, 45, 47, 49, 50, 53, 54, 55, 57, 59, 61, 62, 63, 65, 66, 67, 69, 71, 73, 74, 75, 77, 79, 81, 82, 83, 86, 87, 89, 91, 92, 93, 94, 95, 97, 98, 99, 101, 103, 105, 106, 107, 108, 109, 110, 111, 113, 114, 115 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..66.

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

EXAMPLE

7 is in the sequence because 2^2^7 = 2^128 == 4 mod 7, but 2^^7 = 2^2^2^2^2^2^2 == 2 mod 7.

CROSSREFS

Cf. A092188, A162002, A014221

Sequence in context: A023389 A248963 A221636 * A055741 A103621 A081239

Adjacent sequences:  A162015 A162016 A162017 * A162019 A162020 A162021

KEYWORD

easy,nonn

AUTHOR

Robert Munafo, Jun 24 2009

STATUS

approved

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Last modified August 17 18:38 EDT 2017. Contains 290655 sequences.