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 A072013 #8 Dec 23 2019 06:03:09 %S A072013 1,2,4,5,7,8,10,14,16,17,19,20,25,28,29,31,32,34,35,38,40,41,43,49,50, %T A072013 56,58,62,64,68,70,76,80,82,85,86,95,98,100,101,103,112,116,119,124, %U A072013 125,128,133,136,137,139,140,145,149,151,152,155,160,164 %N A072013 Numbers k such that A072012(k) = k. %H A072013 Amiram Eldar, <a href="/A072013/b072013.txt">Table of n, a(n) for n = 1..10000</a> %Y A072013 Cf. A072010, A072011, A072012. %K A072013 nonn %O A072013 1,2 %A A072013 _Reinhard Zumkeller_, Jun 05 2002