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 A287601 #6 Feb 16 2025 08:33:46
%S A287601 1,1,0,2,1,1,3,1,3,3,4,2,4,4,6,4,6,3,7,5,9,4,11,3,11,4,12,4,11,6,14,3,
%T A287601 13,7,15,8,17,3,18,7,17,5,20,4,20,4,21,11,22,6,24,5,22,10,26,4,26,5,
%U A287601 26,6,24,12,29,13,28,9,32,13,30,9,32,7,33,8,35,17,31,16,38,14,37,6,40,18,33,20
%N A287601 a(0) = a(1) = 1; a(2*n) = n - a(a(n)), a(2*n+1) = a(a(n)) + a(n-a(n)).
%C A287601 A variation on Hofstadter's G-sequence and Hofstadter-Conway $10000 sequence.
%H A287601 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/HofstadterG-Sequence.html">Hofstadter G-Sequence</a>
%H A287601 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/Hofstadter-Conway10000-DollarSequence.html">Hofstadter-Conway 10000-Dollar Sequence</a>
%H A287601 <a href="/index/Ho#Hofstadter">Index entries for Hofstadter-type sequences</a>
%t A287601 a[0] = 1; a[1] = 1; a[n_] := If[EvenQ[n], n/2 - a[a[n/2]], a[a[(n - 1)/2]] + a[(n - 1)/2 - a[(n - 1)/2]]]; Table[a[n], {n, 0, 85}]
%Y A287601 Cf. A004001, A005206, A287475, A287476, A287477, A287597.
%K A287601 nonn
%O A287601 0,4
%A A287601 _Ilya Gutkovskiy_, May 27 2017