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 A358919 #10 Dec 12 2022 12:14:46 %S A358919 0,1,3,1,4,1,5,5,10,4,12,18,1,13,8,22,44,7,52,1,19,35,10,43,53,7,68,1, %T A358919 31,24,56,73,8,126,105,35,71,36,71,60,70,1,124,180,10,172,41,182,40, %U A358919 288,1,232,15,201,4,271,6,213,1,233,14,230,25,216,9,157,115 %N A358919 a(0) = 0, and for any n >= 0, a(n+1) is the sum of the lengths of the runs of consecutive terms a(i), ..., a(j) with 0 <= i <= j <= n such that a(i) XOR ... XOR a(j) = a(n) (where XOR denotes the bitwise XOR operator). %C A358919 The sequence is unbounded (if the sequence was bounded, with greatest value m, then, by the pigeonhole principle, some value, say v, would appear infinitely many times, and the next value after the (m+1)-th occurrence of v would be > m, a contradiction). %H A358919 Rémy Sigrist, <a href="/A358919/b358919.txt">Table of n, a(n) for n = 0..15722</a> %H A358919 Rémy Sigrist, <a href="/A358919/a358919.txt">C program</a> %H A358919 Rémy Sigrist, <a href="/A358919/a358919.png">Scatterplot of the first 350000 terms</a> %e A358919 The first terms, alongside the corresponding pairs (i,j), are: %e A358919 n a(n) (i,j)'s %e A358919 -- ---- --------------------------------- %e A358919 0 0 N/A %e A358919 1 1 (0,0) %e A358919 2 3 (0,1), (1,1) %e A358919 3 1 (2,2) %e A358919 4 4 (0,1), (1,1), (3,3) %e A358919 5 1 (4,4) %e A358919 6 5 (0,1), (1,1), (3,3), (5,5) %e A358919 7 5 (3,4), (4,5), (6,6) %e A358919 8 10 (3,4), (4,5), (4,7), (6,6), (7,7) %e A358919 9 4 (6,8), (8,8) %e A358919 10 12 (3,5), (3,7), (4,4), (5,6), (9,9) %e A358919 11 18 (0,8), (1,8), (10,10) %e A358919 12 1 (11,11) %o A358919 (C) See Links section. %Y A358919 Cf. A358799, A358918. %K A358919 nonn,base %O A358919 0,3 %A A358919 _Rémy Sigrist_, Dec 06 2022