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 A190721 #14 Apr 24 2020 04:02:29 %S A190721 3,5,6,10,13,14,17,21,23,24,28,31,32,35,39,42,43,46,50,52,53,57,60,61, %T A190721 64,68,70,71,75,78,79,82,86,89,90,93,97,99,100,104,107,108,111,115, %U A190721 118,119,122,126,128,129,133,136,137,140,144,146,147,151 %N A190721 Numbers k such that A055778(k) = A055778(k-1). %H A190721 Amiram Eldar, <a href="/A190721/b190721.txt">Table of n, a(n) for n = 1..10000</a> %Y A190721 Cf. A055778, A190720. %K A190721 nonn,base %O A190721 1,1 %A A190721 _Carmine Suriano_, May 17 2011