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 A271864 #7 Apr 19 2016 02:37:19 %S A271864 1,2,4,3,10,6,7,5,20,8,11,9,22,14,16,13,19,15,12,31,42,17,24,21,18,27, %T A271864 29,26,23,36,28,25,34,37,35,39,41,32,30,33,49,51,44,46,43,40,67,45,38, %U A271864 52,47,64,54,56,53,50,61,55,48,65,87,58,63,60,62,85,57 %N A271864 Inverse of A271863. %H A271864 Max Barrentine, <a href="/A271864/b271864.txt">Table of n, a(n) for n = 1..1008</a> %Y A271864 Cf. A271863. %K A271864 nonn %O A271864 1,2 %A A271864 _Max Barrentine_, Apr 16 2016