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 A118762 #4 Mar 30 2012 18:50:54 %S A118762 1,1,1,1,1,1,1,1,1,10,-1,-1,-1,-1,-1,-1,-1,-1,-1,10,1,1,1,1,1,1,1,1,1, %T A118762 10,-1,-1,-1,-1,-1,-1,-1,-1,-1,10,1,1,1,1,1,1,1,1,1,10,-1,-1,-1,-1,-1, %U A118762 -1,-1,-1,-1,10,1,1,1,1,1,1,1,1,1,10,-1,-1,-1,-1,-1,-1,-1,-1,-1,10,1,1,1,1,1,1,1,1,1,10,-1,-1,-1,-1,-1,-1,-1,-1,-1 %N A118762 First differences of A118757. %C A118762 a(10^k-1) = 10^k for 0<k<=3, but a(9999)=-1, a(9998)=10000; %C A118762 abs(a(n)) = 10^k not for all n: e.g. a(1155) = A118757(1156) - A118757(1155) = 1123 - 1121 = 2. %Y A118762 Cf. A118768. %K A118762 sign %O A118762 1,10 %A A118762 _Reinhard Zumkeller_, May 01 2006