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
Amiram Eldar, Table of n, a(n) for n = 1..10000
MATHEMATICA
CarmichaelNbrQ[n_] := ! PrimeQ@ n && Mod[n, CarmichaelLambda@ n] == 1; Select[ Range@ 42000, PrimeQ[# + 1] && PrimeQ[2# + 1] && PrimeQ[9# + 1] && CarmichaelNbrQ[(# + 1)(2# + 1)(9# + 1)] &] (* Robert G. Wilson v, Aug 23 2012 *)
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Sep 23 2001
EXTENSIONS
Offset corrected by Amiram Eldar, Oct 16 2019
STATUS
approved