A072874 Numbers k such that A000213(k) == 1 (mod k).

1, 2, 4, 8, 16, 24, 28, 32, 36, 47, 53, 56, 64, 72, 80, 94, 103, 106, 128, 163, 192, 199, 206, 256, 257, 269, 311, 326, 336, 384, 397, 398, 401, 419, 421, 456, 499, 512, 514, 536, 538, 587, 599, 617, 622, 683, 700, 757, 768, 773, 794, 802, 838, 842, 863, 883, 907

Offset: 1

Author

Benoit Cloitre, Jul 28 2002

Keywords

• easy
• nonn

Comments

Includes A000079. - Robert Israel, Jul 23 2024

Links

• Amiram Eldar, Table of n, a(n) for n = 1..10000

Crossrefs

Cf. A000213, A023173.

Programs

Mathematica

m = 1000; t = LinearRecurrence[{1, 1, 1}, {1, 1, 3}, m]; Position[(t - 1)/Range[m], ?IntegerQ] // Flatten (* _Amiram Eldar, May 05 2022 *)

Extensions

a(1) = 1 inserted by Amiram Eldar, May 05 2022