OFFSET
1,2
COMMENTS
A046025 is a subsequence giving the values of m for which the three factors are prime, which is a sufficient condition for the product (6m+1)(12m+1)(18m+1) to be a Carmichael number.
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000 (terms 1..1000 from Bruno Berselli)
Harvey Dubner, Carmichael Numbers of the form (6m+1)(12m+1)(18m+1), Journal of Integer Sequences, Vol. 5 (2002) Article 02.2.1.
GĂ©rard P. Michon, Generic Carmichael Numbers.
MATHEMATICA
CarmichaelNbrQ[n_] := ! PrimeQ@ n && Mod[n, CarmichaelLambda@ n] == 1; Select[ Range@ 1200, CarmichaelNbrQ[(6# + 1)(12# + 1)(18# + 1)] &] (* Robert G. Wilson v, Aug 23 2012 *)
PROG
(Magma) [n: n in [1..1200] | IsOne(t mod CarmichaelLambda(t)) where t is (6*n+1)*(12*n+1)*(18*n+1)]; // Bruno Berselli, Jan 22 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Gerard P. Michon, Dec 03 2004
STATUS
approved