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A064250
Values of m such that N=(am+1)(bm+1)(cm+1) is a 3-Carmichael number (A087788), where a,b,c = 1,2,27.
1
606, 2280, 3036, 3738, 7950, 15348, 16266, 20640, 21558, 23826, 26040, 27066, 28686, 30576, 31386, 31656, 32358, 33870, 36570, 47856, 49476, 53148, 57036, 64920, 65028, 70536, 72480, 80526, 85818, 86466, 92568, 94350, 96996, 102828
OFFSET
1,1
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
MATHEMATICA
CarmichaelNbrQ[n_] := ! PrimeQ@ n && Mod[n, CarmichaelLambda@ n] == 1; Select[ Range@ 105000, PrimeQ[# + 1] && PrimeQ[2# + 1] && PrimeQ[27# + 1] && CarmichaelNbrQ[(# + 1)(2# + 1)(27# + 1)] &] (* Robert G. Wilson v, Aug 23 2012 *)
CROSSREFS
Cf. A087788.
Sequence in context: A228036 A274765 A249524 * A186818 A283639 A332160
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Sep 23 2001
EXTENSIONS
Offset corrected by Amiram Eldar, Oct 17 2019
STATUS
approved