A067697 Numbers k such that prime(k) == 1 (mod sigma(k)).

1, 3, 6, 7, 58, 79, 191, 339, 443, 516, 1185, 6275, 20456, 21471, 27341, 40123, 40143, 49678, 50684, 108977, 136023, 251789, 432185, 705256, 2582498, 2879786, 3142462, 3556591

Offset

1,2

Links

Table of n, a(n) for n=1..28.

Mathematica

Select[Range[3560000], Mod[Prime[#]-1, DivisorSigma[1, #]]==0&] (* Harvey P. Dale, Sep 23 2021 *)

Crossrefs

Cf. A067696, A071170.

Sequence in context: A352920 A233209 A186521 * A137128 A256372 A330890

Adjacent sequences: A067694 A067695 A067696 * A067698 A067699 A067700

Keyword

nonn

Author

Benoit Cloitre, Feb 05 2002

Extensions

More terms from Labos Elemer, May 15 2002

Status

approved