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Numbers m such that N = (am+1)(bm+1)(cm+1) is a 3-Carmichael number (A087788), where a,b,c = 1,2,53.
9

%I #14 Oct 17 2019 16:17:54

%S 6120,11526,104700,108516,115830,122826,297726,298680,320940,338430,

%T 339066,367686,374046,387720,448140,531456,534636,538770,587106,

%U 618270,709536,746106,762006,857406,863766,897156,963300,1115940,1150920

%N Numbers m such that N = (am+1)(bm+1)(cm+1) is a 3-Carmichael number (A087788), where a,b,c = 1,2,53.

%H Amiram Eldar, <a href="/A065695/b065695.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@ 1000000, PrimeQ[# + 1] && PrimeQ[2# + 1] && PrimeQ[53# + 1] && CarmichaelNbrQ[(# + 1)(2# + 1)(53# + 1)] &] (* _Robert G. Wilson v_, Aug 23 2012 *)

%Y Cf. A064238-A064262, A065696-A065703, A087788.

%K nonn

%O 1,1

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

%E More terms from _Robert G. Wilson v_, Aug 23 2012