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 A087470 #9 May 23 2015 18:45:51 %S A087470 1,2,1,3,2,4,1,3,5,2,4,1,6,3,5,2,7,4,1,6,3,8,5,2,7,4,1,9,6,3,8,5,2,10, %T A087470 7,4,1,9,6,3,11,8,5,2,10,7,4,1,12,9,6,3,11,8,5,2,13,10,7,4,1,12,9,6,3, %U A087470 14,11,8,5,2,13,10,7,4,1,15,12,9,6,3,14,11,8,5,2,16,13,10,7,4,1,15,12,9,6 %N A087470 a(n) = number of the row (counting from initial row 1) of the array R in A087468 that contains n. %C A087470 A fractal sequence. %H A087470 Clark Kimberling and John E. Brown, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL7/Kimberling/kimber67.html">Partial Complements and Transposable Dispersions</a>, J. Integer Seqs., Vol. 7, 2004. %e A087470 Northwest corner of R: %e A087470 1 3 7 12 19 %e A087470 2 5 10 16 24 %e A087470 4 8 14 21 30 %e A087470 6 11 18 26 36 %e A087470 9 15 23 32 43 %e A087470 a(11)=4 because 11 is in row 4. %Y A087470 Cf. A087468, A087469. %K A087470 nonn %O A087470 1,2 %A A087470 _Clark Kimberling_, Sep 09 2003