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 A380751 #13 Feb 07 2025 05:37:47 %S A380751 1,1,2,1,2,2,2,1,3,3,3,4,3,4,4,1,2,3,4,5,5,5,4,5,6,6,5,6,7,6,7,1,5,2, %T A380751 6,3,7,7,8,8,6,7,8,9,8,9,4,9,9,8,10,7,10,9,10,10,8,11,10,9,11,11,11,1, %U A380751 10,12,12,2,11,12,13,3,12,9,12,11,10,13,13,12 %N A380751 Lexicographically earliest sequence of positive integers such that for any value k, no two sets of one or more indices at which k occurs have the same sum. %C A380751 The longest run in the sequence has length 3. %C A380751 The powers of 2 (A000079) are the indices of 1s in this sequence. %H A380751 Neal Gersh Tolunsky, <a href="/A380751/b380751.txt">Table of n, a(n) for n = 1..10000</a> %e A380751 a(3) cannot be 1 since i = 1,2 would have the same sum as i = 3. So a(3) = 2. %e A380751 a(12) cannot be 1 since i = 4,8 would have the same sum as i = 12. a(12) = 2 would give i = 12 the same sum as i = 5,7. a(12) = 3 would give i = 10,11 the same sum as i = 9,12. So a(12) = 4. %Y A380751 Cf. A380783. %K A380751 nonn %O A380751 1,3 %A A380751 _Neal Gersh Tolunsky_, Jan 31 2025