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 A171520 #8 Sep 01 2019 08:44:12 %S A171520 1,3,4,5,7,8,9,10,11,12,13,14,16,17,18,19,20,21,22,23,24,25,26,27,29, %T A171520 30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52, %U A171520 53,54,56,57,58,59,60,61,62,63,64,65,66,67,68,69,70,71,72,73,74,75,76,77,79 %N A171520 Integers m that are not the product of k-th prime and k for any k >= 1. %C A171520 Complement of A033286. %Y A171520 Cf. A033286. %K A171520 nonn,less %O A171520 1,2 %A A171520 _Jaroslav Krizek_, Dec 11 2009 %E A171520 More terms from _Michel Marcus_, Aug 31 2019