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 A108715 #21 Nov 26 2020 16:40:35 %S A108715 0,1,-1,2,-1,2,-3,4,-2,3,-4,5,-3,4,-7,8,-4,5,-7,8,-5,6,-10,11,-6,7, %T A108715 -10,11,-7,8,-15,16,-8,9,-13,14,-9,10,-17,18,-10,11,-16,17,-11,12,-22, %U A108715 23,-12,13,-19,20,-13,14,-24,25,-14,15,-22,23,-15,16,-31,32,-16,17,-25,26,-17,18,-31,32,-18,19,-28,29,-19,20,-37,38,-20 %N A108715 First differences of A025480. %C A108715 Pattern: cycles of four successive terms. [this needs to be clarified, _Joerg Arndt_, Apr 16 2011] %H A108715 Clark Kimberling, <a href="http://faculty.evansville.edu/ck6/integer/fractals.html">fractal sequences</a>. %F A108715 From _Paul Curtz_, Apr 15 2011: (Start) %F A108715 a(A000225(n)) = A131577(n). %F A108715 2 * a(n) = A000265(n+1) - A000265(n). %F A108715 a(2*n) + a(1+2*n) = 1. %F A108715 a(4*n) = -n, a(1+4*n) = n. %F A108715 a(2+8*n) = 1 + 3*n, a(3+8*n) = 2+3*n. %F A108715 a(2+2*n) = a(n) - a(1+2*n). (End) %Y A108715 Cf. A003602, A025480, A108202, A108686, A108685. %K A108715 base,easy,sign %O A108715 0,4 %A A108715 _Alexandre Wajnberg_, Jun 20 2005