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 A129681 #6 Aug 05 2019 14:37:09
%S A129681 1,4,-2,0,-2,-1,1,4,-2,-1,0,-2,1,6,-2,0,-2,-1,0,-2,1,2,-2,-1,1,4,-2,0,
%T A129681 -2,-1,1,4,-2,-1,0,-2,1,2,-2,-1,1,6,-2,0,-2,-1,0,-2,1,4,-2,0,-2,-1,1,
%U A129681 4,-2,-1,0,-2,1,6,-2,0,-2,-1,0,-2,1,2,-2,-1,1,6,-2,0,-2,-1,0,-2,1,4,-2,0,-2,-1,1,4,-2,-1,0,-2,1,2,-2,-1,1,4,-2
%N A129681 Distance sequence of A129677: A129677(n)-n.
%C A129681 The numbers in this sequence seem to be in the range of [ -2,6], but they are never 3 nor 5 (tested up to 10^4). The relative density of the values {-2,-1,0,1,2,4,6} asymptotically is {8,4,4,4,1,2,1}.
%Y A129681 Distance of A129677, Cf. A129678, A129679, A129680 and A000069.
%K A129681 sign
%O A129681 1,2
%A A129681 Ferenc Adorjan (fadorjan(AT)freemail.hu or ferencadorjan(AT)gmail.com), May 01 2007