A064244 Values of m such that N=(am+1)(bm+1)(cm+1) is a 3-Carmichael number (A087788), where a,b,c = 1,2,15.

36, 156, 306, 546, 576, 606, 726, 1236, 1296, 1626, 1656, 2616, 2706, 3036, 3186, 3606, 3696, 4566, 5166, 5556, 6216, 6966, 7296, 7536, 7866, 8286, 9156, 10176, 10266, 10596, 11496, 14406, 16086, 16416, 16746, 18396, 18636, 18786, 19476

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@ 20000, PrimeQ[# + 1] && PrimeQ[2# + 1] && PrimeQ[15# + 1] && CarmichaelNbrQ[(# + 1)(2# + 1)(15# + 1)] &] (* Robert G. Wilson v, Aug 23 2012 *)

Extensions

Offset corrected by Amiram Eldar, Oct 16 2019