A268597 Smallest x such that x-1 mod phi(x) = n, or 0 if no such x exists.

1, 4, 9, 8, 25, 18, 15, 16, 21, 50, 35, 36, 33, 98, 39, 32, 65, 54, 51, 100, 45, 70, 95, 72, 69, 338, 63, 196, 161, 110, 87, 64, 93, 130, 75, 108, 217, 182, 99, 200, 185, 170, 123, 140, 117, 190, 215, 144, 141, 250, 235

Offset: 0

Author

Christina Steffan, Feb 08 2016

Keywords

• nonn

Comments

Conjecture: a(n) > 0 for all n.

Crossrefs

Cf. A215486.

Programs

PARI

a(n) = {my(x = 1); while ((x-1) % eulerphi(x) != n, x++); x;} \\ Michel Marcus, Feb 27 2016