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Values of m such that N = (am+1)(bm+1)(cm+1) is a 3-Carmichael number (A087788), where a,b,c = 1,2,57.
4

%I #12 Oct 17 2019 16:19:24

%S 198,996,2706,9090,13536,16728,25620,33486,34056,35310,41010,53550,

%T 58566,60960,61986,63240,72816,72930,74526,75780,77490,80340,83760,

%U 96756,97326,100746,103140,111918,125028,125370,128676,129360,136656,164700,174048,175758,176898

%N Values of m such that N = (am+1)(bm+1)(cm+1) is a 3-Carmichael number (A087788), where a,b,c = 1,2,57.

%H Amiram Eldar, <a href="/A065697/b065697.txt">Table of n, a(n) for n = 1..10000</a>

%F am+1, bm+1, cm+1 are primes and am|(N-1), bm|(N-1), cm|(N-1).

%t CarmichaelNbrQ[n_] := ! PrimeQ@n && Mod[n, CarmichaelLambda@n] == 1; Select[ Range@140000, PrimeQ[# +1] && PrimeQ[2# +1] && PrimeQ[57# +1] && CarmichaelNbrQ[(# +1) (2# +1) (57# +1)] &] (* _Robert G. Wilson v_, Jul 31 2017 *)

%Y Cf. A064238-A064262, A065695-A065703, A087788.

%K nonn

%O 1,1

%A Harvey Dubner (harvey(AT)dubner.com), Nov 14 2001

%E More terms from _Amiram Eldar_, Oct 17 2019