This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.
%I A064240 #12 Oct 16 2019 08:43:52 %S A064240 30,156,618,660,1626,2550,4230,4356,4566,5658,6120,6708,7506,11496, %T A064240 15318,16746,18048,19140,19476,19686,20610,21030,22920,23130,24096, %U A064240 25188,26406,27918,29346,29598,29640,32748,33966,35058,39678,41610 %N A064240 Values of m such that N=(am+1)(bm+1)(cm+1) is a 3-Carmichael number (A087788), where a,b,c = 1,2,7. %C A064240 am+1, bm+1, cm+1 are primes and am | (N-1), bm | (N-1), cm |(N-1). %D A064240 Harvey Dubner (harvey(AT)dubner.com), personal communication, Jun 27 2001. %H A064240 Amiram Eldar, <a href="/A064240/b064240.txt">Table of n, a(n) for n = 1..10000</a> %t A064240 CarmichaelNbrQ[n_] := ! PrimeQ@ n && Mod[n, CarmichaelLambda@ n] == 1; Select[ Range@ 42000, PrimeQ[# + 1] && PrimeQ[2# + 1] && PrimeQ[7# + 1] && CarmichaelNbrQ[(# + 1)(2# + 1)(7# + 1)] &] (* _Robert G. Wilson v_, Aug 23 2012 *) %Y A064240 Cf. A087788. %K A064240 nonn %O A064240 1,1 %A A064240 _N. J. A. Sloane_, Sep 23 2001 %E A064240 Offset corrected by _Amiram Eldar_, Oct 16 2019