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 A143717 #6 Mar 30 2012 18:52:27 %S A143717 4,5,8,4,5,7,12,1,19,3,15,5,32,4,1,7,7,24,28,9,20,3,36,20,8,38,47,11, %T A143717 4,68,5,3,0,13,42,5,6,15,86,3,58,26,1,10,75,17,22,73,4,73,29,2,1,14, %U A143717 73,2,122,3,15,44,24,80,4,8,24,18,16,95,7,10,5,101,117,14,9,158,3,108,9,31 %N A143717 (1, 2, 3, 2^2, 5, 2*3, 7, 2^3, 3^2, 2*5, 11, 2^2*3, 13, 2*7, 3*5,..) becomes (abs(1-2-3, 2-2-5, 2-3-7, 2-3-3, 2-2-5, 11-2-2, 3-13-2, 7-3-5,..)). %e A143717 Abs (7-3-5)=abs (-1) =1=a(8). %e A143717 Abs (2-4-17)=abs(-19)=19=a(9). %e A143717 Abs (2-3-2)=abs (-3)=3=a(10). %e A143717 Abs (19-2-2)=abs 15=15=a(11), %e A143717 Abs (5-3-7)=abs (-5)=5=a(12), %e A143717 etc. %Y A143717 Cf. A141287, A141261, A136678. %K A143717 nonn,less %O A143717 1,1 %A A143717 _Juri-Stepan Gerasimov_, Nov 13 2008 %E A143717 Replaced a 56 by a 1. _R. J. Mathar_, Feb 21 2009