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 A163539 #3 Mar 31 2012 13:21:18 %S A163539 0,0,1,0,1,1,0,-1,0,1,0,-1,-1,0,-1,0,0,1,0,-1,0,0,1,0,1,0,1,0,0,-1,0, %T A163539 1,1,1,0,-1,0,0,1,0,1,0,1,0,0,-1,0,1,0,0,-1,0,-1,-1,0,1,0,-1,0,1,1,0, %U A163539 1,0,1,1,0,-1,0,0,1,0,1,0,1,0,0,-1,0,1,1,0,1,0,1,1,0,-1,0,1,0,-1,-1,0 %N A163539 The change in Y-coordinate when moving from the n-1:th to the n-th term in the type I Hilbert's Hamiltonian walk A163357. %H A163539 A. Karttunen, <a href="/A163539/b163539.txt">Table of n, a(n) for n = 0..65536</a> %F A163539 a(0)=0, a(n) = A059252(n) - A059252(n-1). %Y A163539 These are the first differences of A059252. See also: A163538, A163541, A163543. %K A163539 sign %O A163539 0,1 %A A163539 _Antti Karttunen_, Aug 01 2009