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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 = 1,2,55.
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%I #11 Oct 17 2019 16:18:10

%S 3876,7506,8166,16746,20706,23676,24336,40506,42156,68226,69876,79776,

%T 95286,123996,139176,149076,166236,177786,183066,187686,203856,210126,

%U 213096,214086,216396,221676,232566,265566,307146,310116,321006,326946

%N Numbers m such that N = (am+1)(bm+1)(cm+1) is a 3-Carmichael number (A087788), where a,b,c = 1,2,55.

%H Amiram Eldar, <a href="/A065696/b065696.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@ 350000, PrimeQ[# + 1] && PrimeQ[2# + 1] && PrimeQ[55# + 1] && CarmichaelNbrQ[(# + 1)(2# + 1)(55# + 1)] &] (* _Robert G. Wilson v_, Aug 23 2012 *)

%Y Cf. A064238-A064262, A065695, A065696, A065697, A065698, A065699, A065700, A065701, A065703, A087788.

%K nonn

%O 1,1

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