A064249 Values of m such that N=(am+1)(bm+1)(cm+1) is a 3-Carmichael number (A087788), where a,b,c = 1,2,25.

2136, 6036, 7536, 11886, 17136, 18636, 21786, 24336, 27336, 27486, 28386, 28686, 30186, 40086, 50586, 51786, 52836, 59886, 70536, 74286, 85236, 86286, 93786, 95286, 100986, 110586, 111636, 118386, 120936, 125736, 135636

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@ 140000, PrimeQ[# + 1] && PrimeQ[2# + 1] && PrimeQ[25# + 1] && CarmichaelNbrQ[(# + 1)(2# + 1)(25# + 1)] &] (* Robert G. Wilson v, Aug 23 2012 *)

Extensions

Offset corrected by Amiram Eldar, Oct 16 2019