A064252 Values of m such that N=(am+1)(bm+1)(cm+1) is a 3-Carmichael number (A087788), where a,b,c = 1,2,31.

13158, 15390, 16878, 25620, 31386, 36036, 60960, 92580, 109320, 110436, 132756, 136848, 177210, 184650, 236916, 247518, 265560, 273186, 278766, 308526, 314850, 317826, 326940, 333450, 338286, 364140, 376416, 389436, 440958, 447840, 451746, 467556, 476298, 494340

Offset: 1

Author

N. J. A. Sloane, Sep 23 2001

Keywords

• nonn

Comments

am+1, bm+1, cm+1 are primes and am | (N-1), bm | (N-1), cm |(N-1).

References

• Harvey Dubner (harvey(AT)dubner.com), personal communication, Jun 27 2001.

Links

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

Crossrefs

Cf. A087788.

Programs

Mathematica

carmQ[n_] := CompositeQ[n] && Divisible[n - 1, CarmichaelLambda[n]]; Select[Range[10^5], AllTrue[(v = {1, 2, 31}*# + 1), PrimeQ] && carmQ[Times @@ v] &] (* Amiram Eldar, Oct 17 2019 *)

Extensions

Offset corrected and more terms added by Amiram Eldar, Oct 17 2019