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 A296616 #12 Dec 20 2017 12:13:33 %S A296616 1,2,4,3,6,7,14,8,16,9,18,5,10,11,21,12,22,13,23,27,24,28,26,29,53,31, %T A296616 54,32,56,17,57,35,15,36,61,37,63,19,64,39,33,20,34,41,69,42,71,43,72, %U A296616 44,73,45,74,46,38,47,77,48,78,49,79,25,40,51,81,52,82 %N A296616 Lexicographically earliest sequence of distinct positive terms such that, for any n > 0, the binary expansion of a(n) * a(n + 1) starts with the binary expansion of n. %C A296616 It is likely that this sequence is a permutation of the natural numbers. %C A296616 The lines visible in the scatterplot of the first terms seems to corresponds to set of indices n where the function f(n) = Sum_{k=1..n-1} (-1)^k * (A029837(1+a(k)*a(k+1)) - A029837(1+k)) has the same value; those lines can be partitioned into two groups, depending on the parity of n (see Links section). %C A296616 This sequence has connections with A272679: here the binary expansion of a(n)*a(n+1) starts with that of n, there the binary expansion of a(n)^2 starts with that of n. %H A296616 Rémy Sigrist, <a href="/A296616/b296616.txt">Table of n, a(n) for n = 1..10000</a> %H A296616 Rémy Sigrist, <a href="/A296616/a296616.txt">C++ program for A296616</a> %H A296616 Rémy Sigrist, <a href="/A296616/a296616.png">Colored scatterplot of the first 100000 terms</a> (where the color is function of Sum_{k=1..n-1} (-1)^k * (A029837(1+a(k)*a(k+1)) - A029837(1+k))) %H A296616 Rémy Sigrist, <a href="/A296616/a296616_1.png">Colored scatterplot of the first 10000 terms</a> (where the color is function of the parity of n) %e A296616 The first terms, alongside the binary representations of n and a(n) * a(n + 1), are: %e A296616 n a(n) bin(n) bin(a(n)*a(n+1)) %e A296616 -- ---- ------ ---------------- %e A296616 1 1 1 10 %e A296616 2 2 10 1000 %e A296616 3 4 11 1100 %e A296616 4 3 100 10010 %e A296616 5 6 101 101010 %e A296616 6 7 110 1100010 %e A296616 7 14 111 1110000 %e A296616 8 8 1000 10000000 %e A296616 9 16 1001 10010000 %e A296616 10 9 1010 10100010 %e A296616 11 18 1011 1011010 %e A296616 12 5 1100 110010 %e A296616 13 10 1101 1101110 %e A296616 14 11 1110 11100111 %e A296616 15 21 1111 11111100 %e A296616 16 12 10000 100001000 %e A296616 17 22 10001 100011110 %e A296616 18 13 10010 100101011 %e A296616 19 23 10011 1001101101 %e A296616 20 27 10100 1010001000 %o A296616 (C++) See Links section. %Y A296616 Cf. A029837, A272679. %K A296616 nonn,base %O A296616 1,2 %A A296616 _Rémy Sigrist_, Dec 17 2017