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 A153580 #18 Jun 24 2019 11:07:11 %S A153580 721801,873181,4504501,8646121,9006401,9863461,10403641,12322133, %T A153580 14609401,15913261,18595801,18736381,20234341,21397381,22066201, %U A153580 22369621,22885129,25326001,25696133,28312921,36307981,42702661 %N A153580 Terms of A083737 which are not Carmichael numbers (A002997). %H A153580 Amiram Eldar, <a href="/A153580/b153580.txt">Table of n, a(n) for n = 1..2871</a> (calculated from the b-file at A083737) %t A153580 Select[Range[5*10^7], ! PrimeQ[ # ] && PowerMod[2, # - 1, # ] == 1 && PowerMod[3, # - 1, # ] == 1 && PowerMod[5, # - 1, # ] == 1 && Mod[ #, CarmichaelLambda[ # ]] != 1 &] (* _Ray Chandler_, Dec 28 2008 *) %Y A153580 Cf. A002997, A083737, A122780, A153508, A153513, A153514, A153515, A153519, A153581. %K A153580 nonn %O A153580 1,1 %A A153580 _Ray Chandler_ & _Artur Jasinski_, Dec 28 2008