A064243 Values of m such that N=(am+1)(bm+1)(cm+1) is a 3-Carmichael number (A087788), where a,b,c = 1,2,13.

96, 1656, 2280, 5556, 6960, 7506, 8286, 12420, 12966, 15540, 17490, 23496, 26226, 28410, 32076, 33870, 42060, 53526, 57036, 61560, 67956, 73416, 89796, 104850, 107580, 108516, 122166, 124350, 126690, 132150, 143616, 148920

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

CarmichaelNbrQ[n_] := ! PrimeQ@ n && Mod[n, CarmichaelLambda@ n] == 1; Select[ Range@ 150000, PrimeQ[# + 1] && PrimeQ[2# + 1] && PrimeQ[13# + 1] && CarmichaelNbrQ[(# + 1)(2# + 1)(13# + 1)] &] (* Robert G. Wilson v, Aug 23 2012 *)

Extensions

Offset corrected by Amiram Eldar, Oct 16 2019