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 A153515 #12 Sep 19 2019 19:16:16 %S A153515 1,4,10,15,20,65,124,190,217,310,435,781,1541,1891,3565,3820,4123, %T A153515 4495,5461,5611,5662,5731,6735,7449,7813,8029,8290,9881,11041,11476, %U A153515 12801,13021,13333,13981,14981,15751,16297,17767,20345,20710,21361,22791 %N A153515 Terms of A122782 which are not Carmichael numbers A002997. %C A153515 Are there entries in this sequence which are also in A153513 ? %C A153515 Yes. This subsequence starts 721801, 873181, 4504501, 8646121, 9006401, 9863461, 10403641, 10680265,... (similar to A153580). - _R. J. Mathar_, Mar 30 2011 %H A153515 Amiram Eldar, <a href="/A153515/b153515.txt">Table of n, a(n) for n = 1..10000</a> %t A153515 Select[Range[10^4], !PrimeQ[#] && PowerMod[5, #, # ] == Mod[5, #] && Mod[#, CarmichaelLambda[#]] != 1 &] (* _Amiram Eldar_, Sep 19 2019 *) %Y A153515 Cf. A002997, A122780, A153508, A153513. %K A153515 nonn %O A153515 1,2 %A A153515 _Artur Jasinski_, Dec 28 2008