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 A376733 #7 Oct 03 2024 11:03:20 %S A376733 0,1,2,4,5,3,10,8,9,11,18,6,20,21,7,19,22,36,16,40,41,17,37,23,14,12, %T A376733 13,15,42,82,38,44,32,72,73,33,45,39,83,43,74,34,46,80,81,47,35,75,26, %U A376733 30,28,24,25,29,31,27,78,164,84,144,64,88,89,65,145,85,165 %N A376733 a(1) = 0; for any any n > 1, if A376637(n) starts with a digit 1 then a(n) = 2*a(A376676(n)) otherwise a(n) = 2*a(A376676(n)) + 1. %C A376733 The binary expansion of a(n) encodes the position of A376637(n) within the binary tree underlying A376676 (see illustration in Links section). %C A376733 This sequence is a bijection from the positive integers to the nonnegative integers. %H A376733 Rémy Sigrist, <a href="/A376733/b376733.txt">Table of n, a(n) for n = 1..10048</a> %H A376733 Rémy Sigrist, <a href="/A376733/a376733.png">Illustration of terms < 32</a> (where b = A376637) %H A376733 Rémy Sigrist, <a href="/A376733/a376733.gp.txt">PARI program</a> %H A376733 <a href="/index/Per#IntegerPermutation">Index entries for sequences that are permutations of the natural numbers</a> %F A376733 A070939(a(n)) = A376698(n) for any n > 0. %e A376733 See illustration in Links section. %o A376733 (PARI) \\ See Links section. %Y A376733 Cf. A070939, A376637, A376676, A376698. %K A376733 nonn,base %O A376733 1,3 %A A376733 _Rémy Sigrist_, Oct 03 2024