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 A064241 #13 Oct 16 2019 11:27:54 %S A064241 30,228,498,1398,1758,2028,2280,3180,4800,5430,6150,6420,6708,7950, %T A064241 8688,9930,11838,13728,16518,16878,17490,19488,26040,28200,30108, %U A064241 30468,33528,33870,34140,34500,35490,35670,38298,38820,39900,40350 %N A064241 Values of m such that N=(am+1)(bm+1)(cm+1) is a 3-Carmichael number (A087788), where a,b,c = 1,2,9. %C A064241 am+1, bm+1, cm+1 are primes and am | (N-1), bm | (N-1), cm |(N-1). %D A064241 Harvey Dubner (harvey(AT)dubner.com), personal communication, Jun 27 2001. %H A064241 Amiram Eldar, <a href="/A064241/b064241.txt">Table of n, a(n) for n = 1..10000</a> %t A064241 CarmichaelNbrQ[n_] := ! PrimeQ@ n && Mod[n, CarmichaelLambda@ n] == 1; Select[ Range@ 42000, PrimeQ[# + 1] && PrimeQ[2# + 1] && PrimeQ[9# + 1] && CarmichaelNbrQ[(# + 1)(2# + 1)(9# + 1)] &] (* _Robert G. Wilson v_, Aug 23 2012 *) %Y A064241 Cf. A087788. %K A064241 nonn %O A064241 1,1 %A A064241 _N. J. A. Sloane_, Sep 23 2001 %E A064241 Offset corrected by _Amiram Eldar_, Oct 16 2019