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 A029884 #6 Jul 08 2025 19:24:27 %S A029884 -1,-1,2,-2,1,1,-1,-1,1,1,-2,2,-1,-1,2,-2,1,1,-2,2,-1,-1,1,1,-1,-1,2, %T A029884 -2,1,1,-1,-1,1,1,-2,2,-1,-1,1,1,-1,-1,2,-2,1,1,-2,2,-1,-1,2,-2,1,1, %U A029884 -1,-1,1,1,-2,2,-1,-1,2,-2,1,1,-2,2,-1,-1,1,1,-1,-1,2,-2,1,1,-2,2,-1 %N A029884 Second differences of Thue-Morse sequence A001285. %K A029884 sign %O A029884 0,3 %A A029884 _N. J. A. Sloane_