A337612 Positive integers m such that A126289^k(m) = m for some positive integer k.

1, 6, 10, 15, 20, 21, 35, 38, 42, 45, 52, 58, 63, 66, 68, 74, 76, 77, 78, 84, 85, 88, 92, 99, 110, 116, 117, 124, 130, 133, 143, 146, 153, 164, 171, 187, 189, 198, 208, 224, 228, 232, 238, 246, 247, 255, 261, 266, 268, 272, 273, 279, 282, 284, 285, 304, 312

Offset

1,2

Comments

A126289^k(m) means apply A126289 to m k times.

Equivalently, the numbers that belong to a cycle under the map x -> A126289(x).

There are no primes in this sequence.

Links

Ely Golden, Table of n, a(n) for n = 1..10000

Ely Golden, Python program for (naïvely) generating terms of this sequence

Formula

For any term m, gcd {m, A126289(m), A126289(A126289(m)), ...} = A052126(m).

Example

6 is a term since A126289(A126289(6)) = A126289(10) = 6.

Crossrefs

Cf. A052126, A126289, A337609, A337610, A337611.

Sequence in context: A319382 A006987 A182237 * A315250 A315251 A315252

Adjacent sequences: A337609 A337610 A337611 * A337613 A337614 A337615

Keyword

nonn

Author

Ely Golden, Oct 06 2020

Status

approved