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 A226248 #4 Jun 07 2013 14:56:56 %S A226248 0,1,2,-1,3,-1,4,-1,1,5,-1,2,3,-2,6,-1,3,5,-3,5,-2,7,-1,4,7,-4,8,-3,7, %T A226248 -2,1,8,-1,5,9,-5,11,-4,11,-3,2,9,-2,3,4,-3,9,-1,6,11,-6,14,-5,15,-4, %U A226248 3,14,-3,5,7,-5,11,-2,5,8,-5,7,-3,10,-1,7,13,-7 %N A226248 Numerators of rational numbers as generated by the rules: 0 is in S; if x is in S, then x+1 is in S, and if nonzero x is in S, then -1/x are in S. %C A226248 The rational numbers are ordered as a sequence S'' described at A226247. %H A226248 Clark Kimberling, <a href="/A226248/b226248.txt">Table of n, a(n) for n = 1..1000</a> %e A226248 The denominators and numerators are read from S'': %e A226248 0/1, 1/1, 2/1, -1/1, 3, -1/2, 4/1, -1/3, 1/2, 5, -1/4, 2/3, 3/2, -2, ... %t A226248 (See A226247.) %Y A226248 Cf. A226247. %K A226248 sign,easy %O A226248 1,3 %A A226248 _Clark Kimberling_, Jun 01 2013