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 A101188 #15 Mar 27 2021 07:59:49 %S A101188 18,216,24966,228246,299790,403806,413046,446310,514686,760470,948966, %T A101188 1019190,1087566,1355526,1374006,1471950,1582830,1715886,2159406, %U A101188 2266590,2334966,2589990,2833926,3652590,3661830,3720966,3874350 %N A101188 Values of k for which (7*k+1)*(8*k+1)*(11*k+1) is a Carmichael number. %C A101188 All values of n are even (since there are no even Carmichael numbers). Small values happen to be congruent to 18 modulo 66. This first fails for a(34)=5206142, which yields the Carmichael number 86921811895459937817345 = (3*5*29*83777)*41649137*57267563. Below this, only 4 values of n (18, 216, 299790 and 446310) correspond to Carmichael numbers with at least 4 prime factors. Other values of n must be of the form 1848k+942, with k given by A101186. %H A101188 Amiram Eldar, <a href="/A101188/b101188.txt">Table of n, a(n) for n = 1..10000</a> %H A101188 Gérard P. Michon, <a href="http://www.numericana.com/answer/modular.htm#chernik">Generic Carmichael Numbers</a>. %e A101188 a(1) = 18 corresponds to a 4-factor Carmichael number: 3664585 = 127 *(5*29) * 199. %t A101188 CarmichaelNbrQ[n_] := ! PrimeQ[n] && Mod[n, CarmichaelLambda[n]] == 1; Select[ Range[4000000], CarmichaelNbrQ[(7# + 1)(8# + 1)(11# + 1)] &] (* _Robert G. Wilson v_, Aug 24 2012 *) %Y A101188 Cf. A002997 (Carmichael numbers), A101186, A101187. %K A101188 nonn %O A101188 1,1 %A A101188 _Gerard P. Michon_, Dec 08 2004