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 A361144 #17 Mar 07 2023 07:42:28 %S A361144 1,2,4,5,6,7,8,10,11,14,15,17,16,19,20,21,22,23,24,26,27,28,29,30,33, %T A361144 34,36,37,38,39,40,42,44,46,47,49,48,51,52,53,54,56,58,60,61,62,63,64, %U A361144 65,66,68,69,70,71,72,74,75,78,79,81,80,83,84,85,86,87,88 %N A361144 Lexicographically earliest sequence of positive integers such that the sums Sum_{i = 1+k*2^e..(k+1)*2^e} a(i) with k, e >= 0 are all distinct. %C A361144 In other words, a(1), a(2), a(1)+a(2), a(3), a(4), a(3)+a(4), a(1)+a(2)+a(3)+a(4), a(5), a(6), a(5)+a(6), etc. are all distinct (see A361227 for these values). %C A361144 In particular, all terms are distinct (but not necessarily in increasing order). %C A361144 We can arrange the terms of the sequence as the leaves of a perfect infinite binary tree, the sums with e > 0 corresponding to parent nodes; each node will contain a different value and all values will appear in the tree (if n = 2^m+1 for some m > 0, then a(n) will equal the least missing value so far in the tree). %H A361144 Rémy Sigrist, <a href="/A361144/a361144.gp.txt">PARI program</a> %H A361144 Rémy Sigrist, <a href="/A361144/a361144.txt">C++ program</a> %F A361144 Empirically, a(n) ~ 4*n/3 as n tends to infinity. %e A361144 The first terms (at the bottom of the tree) alongside the corresponding sums are: %e A361144 176 %e A361144 --------------------------------- %e A361144 43 133 %e A361144 ----------------- ----------------- %e A361144 12 31 57 76 %e A361144 --------- --------- --------- --------- %e A361144 3 9 13 18 25 32 35 41 %e A361144 ----- ----- ----- ----- ----- ----- ----- ----- %e A361144 1 2 4 5 6 7 8 10 11 14 15 17 16 19 20 21 %o A361144 (PARI) See Links section. %o A361144 (C++) See Links section. %Y A361144 See A360305, A361189, A361191 and A361234 for other variants. %Y A361144 Cf. A326936, A361146, A361227. %K A361144 nonn %O A361144 1,2 %A A361144 _Rémy Sigrist_, Mar 02 2023