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 A159942 #13 Oct 18 2018 22:04:28 %S A159942 2,5,7,10,16,17,19,20,23,29,31,38,41,49,50,55,56,59,61,64,71,76,79,85, %T A159942 92,100,101,103,121,134,136,139,140,143,149,154,155,161,175,176,178, %U A159942 182,184,188,208,209,211,217,220,232,236,239,241,244,265,266,269,271,272 %N A159942 Duplicate of A102339. %Y A159942 Cf. A157772, A102248. %K A159942 dead %O A159942 1,1