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 A258253 #5 Jul 09 2015 11:47:03 %S A258253 1,2,4,5,11,3,14,15,18,8,29,6,46,9,7,47,73,17,134,35,33,26,153,16,96, %T A258253 27,154,34,292,12,269,185,19,85,10,49,240,86,69,21,535,13,536,64,50, %U A258253 271,408,48,213,114,32,63,616,131,36,40,109,580,763,22,1010,270 %N A258253 Putative inverse of A258252. %H A258253 Ivan Neretin, <a href="/A258253/b258253.txt">Table of n, a(n) for n = 1..1000</a> %Y A258253 Cf. A258252. %K A258253 nonn %O A258253 1,2 %A A258253 _Ivan Neretin_, May 24 2015