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 A302840 #15 Mar 17 2025 11:41:15 %S A302840 1,2,3,4,5,10,6,8,7,9,11,12,13,14,15,16,17,18,19,20,22,21,23,26,24,25, %T A302840 29,38,27,28,37,41,31,45,32,35,36,40,30,44,39,46,34,42,33,47,43,48,49, %U A302840 50,51,52,53,74,55,65,82,73,77,83,86,90,56,59,63,64,81 %N A302840 Lexicographically earliest sequence of distinct positive terms such that any n > 0, A065359(a(n)) <= A065368(a(n+1)). %C A302840 See A302839 for a sequence with digital sums instead of alternate digital sums. %H A302840 Rémy Sigrist, <a href="/A302840/b302840.txt">Table of n, a(n) for n = 1..10000</a> %H A302840 Rémy Sigrist, <a href="/A302840/a302840.png">Colored scatterplot of the first 25000 terms</a> (where the color is function of A065368(a(n))) %H A302840 Rémy Sigrist, <a href="/A302840/a302840.gp.txt">PARI program for A302840</a> %H A302840 <a href="/index/Di#digital">Index entries for sequences related to digital root, sum, etc.</a> %e A302840 The first terms, alongside their alternate digital sums in bases 2 and 3, are: %e A302840 n a(n) s2(a(n)) s3(a(n)) %e A302840 -- ---- -------- -------- %e A302840 1 1 1 1 %e A302840 2 2 -1 2 %e A302840 3 3 0 -1 %e A302840 4 4 1 0 %e A302840 5 5 2 1 %e A302840 6 10 -2 2 %e A302840 7 6 0 -2 %e A302840 8 8 -1 0 %e A302840 9 7 1 -1 %e A302840 10 9 0 1 %e A302840 11 11 -1 3 %e A302840 12 12 0 0 %e A302840 13 13 1 1 %e A302840 14 14 -1 2 %e A302840 15 15 0 -1 %e A302840 16 16 1 0 %e A302840 17 17 2 1 %e A302840 18 18 0 2 %e A302840 19 19 1 3 %e A302840 20 20 2 4 %o A302840 (PARI) \\ See Links section. %Y A302840 Cf. A065359, A065368, A302839. %K A302840 nonn,base %O A302840 1,2 %A A302840 _Rémy Sigrist_, Apr 14 2018