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 A018222 #13 Aug 03 2017 01:52:33 %S A018222 5,3,8,1,4,0,9,11,2,6,18,7,13,12,27,22,25,29,10,33,30,38,15,39,35,16, %T A018222 44,14,43,17,20,50,54,19,57,24,56,62,21,23,64,69,63,28,26,74,76,73,75, %U A018222 81,31,87,86,88,32,93,36,34,91,90,101,100,37,42,40,102,106,110,112,41 %N A018222 Row 3 of A018219, i.e., (3,n,a_n) is a winning position. %C A018222 Self-inverse when considered as a permutation or function, i.e., a(a(n)) = n. %H A018222 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %K A018222 nonn %O A018222 0,1 %A A018222 _Michael Kleber_ %E A018222 Edited and extended by _Christian G. Bower_, Oct 29 2002