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 A064250 #13 Oct 17 2019 06:08:31 %S A064250 606,2280,3036,3738,7950,15348,16266,20640,21558,23826,26040,27066, %T A064250 28686,30576,31386,31656,32358,33870,36570,47856,49476,53148,57036, %U A064250 64920,65028,70536,72480,80526,85818,86466,92568,94350,96996,102828 %N A064250 Values of m such that N=(am+1)(bm+1)(cm+1) is a 3-Carmichael number (A087788), where a,b,c = 1,2,27. %C A064250 am+1, bm+1, cm+1 are primes and am | (N-1), bm | (N-1), cm |(N-1). %D A064250 Harvey Dubner (harvey(AT)dubner.com), personal communication, Jun 27 2001. %H A064250 Amiram Eldar, <a href="/A064250/b064250.txt">Table of n, a(n) for n = 1..10000</a> %t A064250 CarmichaelNbrQ[n_] := ! PrimeQ@ n && Mod[n, CarmichaelLambda@ n] == 1; Select[ Range@ 105000, PrimeQ[# + 1] && PrimeQ[2# + 1] && PrimeQ[27# + 1] && CarmichaelNbrQ[(# + 1)(2# + 1)(27# + 1)] &] (* _Robert G. Wilson v_, Aug 23 2012 *) %Y A064250 Cf. A087788. %K A064250 nonn %O A064250 1,1 %A A064250 _N. J. A. Sloane_, Sep 23 2001 %E A064250 Offset corrected by _Amiram Eldar_, Oct 17 2019