A337609 Positive integers m such that A126286^k(m) = m for some positive integer k.

2, 3, 14, 21, 26, 34, 38, 39, 50, 57, 62, 74, 75, 85, 86, 93, 94, 98, 110, 111, 118, 122, 129, 134, 142, 146, 147, 154, 158, 165, 170, 182, 183, 194, 201, 202, 206, 214, 218, 219, 230, 235, 237, 242, 254, 255, 266, 273, 274, 278, 286, 290, 291, 298, 302, 309

Offset: 1

Author

Ely Golden, Oct 07 2020

Keywords

• nonn
• easy

Comments

A126286^k(m) means apply A126286 to m k times.

Equivalently, the numbers that belong to a cycle under the map x -> A126286(x).

For any term m in this sequence, A126286(A126286(m)) = m.

Supersequence of A017545. Moreover, this sequence can be represented as an infinite union of arithmetic progressions.

2 and 3 are the only primes in this sequence.

Examples

			3 is a term since A126286(A126286(3)) = A126286(2) = 3.
		

Links

• Ely Golden, Table of n, a(n) for n = 1..10000
• Ely Golden, Python program for generating terms of this sequence

Crossrefs

Cf. A017545, A126286, A337610, A337611, A337612.