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 A258051 #5 Feb 15 2016 12:19:51 %S A258051 0,0,1,0,2,1,0,2,4,1,3,0,5,2,4,1,3,0,5,2,7,4,1,6,3,0,8,5,2,7,4,1,9,6, %T A258051 3,0,8,5,2,10,7,4,1,9,6,3,0,8,5,2,10,7,4,12,1,9,6,3,11,0,8,5,13,2,10, %U A258051 7,4,12,1,9,6,3,11,0,8,5,13,2,10,7,15,4 %N A258051 Fractal sequence derived from A258033. %C A258051 The sequence is constructed like A258033 is constructed: after partitioning A258033 into segments starting with 0, in each segment the greatest term is to be deleted (see example); %C A258051 this sequence is fractal, i.e. if the first occurrence of each n is removed, the resulting sequence is the original sequence. %H A258051 Reinhard Zumkeller, <a href="/A258051/b258051.txt">Table of n, a(n) for n = 1..10000</a> %e A258051 Segments of A258033 starting with 0, deleted maxima in brackets: %e A258051 . 1: 0 %e A258051 . 2: 0 [2] 1 %e A258051 . 3: 0 2 1 [3] %e A258051 . 4: 0 [5] 2 4 1 3 %e A258051 . 5: 0 5 2 4 1 [6] 3 %e A258051 . 6: 0 [8] 5 2 7 4 1 6 3 %e A258051 . 7: 0 8 5 2 [10] 7 4 1 9 6 3 %e A258051 . 8: 0 8 5 2 10 7 4 1 9 6 3 [11] %e A258051 . 9: 0 8 5 [13] 2 10 7 4 12 1 9 6 3 11 %e A258051 . 10: 0 8 5 13 2 10 7 4 12 1 9 6 [14] 3 11 %e A258051 . 11: 0 8 [16] 5 13 2 10 7 15 4 12 1 9 6 14 3 11 %e A258051 . 12: 0 8 16 5 13 2 10 [18] 7 15 4 12 1 9 17 6 14 3 11 %e A258051 . 13: 0 8 16 5 13 2 10 18 7 15 4 12 1 9 17 6 14 3 11 [19] %e A258051 . 14: 0 8 16 5 13 [21] 2 10 18 7 15 4 12 20 1 9 17 6 14 3 11 19 %e A258051 . 15: 0 8 16 5 13 21 2 10 18 7 15 4 12 20 1 9 17 6 14 [22] 3 11 19 %o A258051 (Haskell) %o A258051 import Data.List (delete) %o A258051 a258051 n = a258051_list !! (n-1) %o A258051 a258051_list = f (tail a258033_list) where %o A258051 f xs = (0 : (delete (maximum ys) ys)) ++ f zs %o A258051 where (ys, (_ : zs)) = span (> 0) xs %Y A258051 %Cf. A258033, A022328. %K A258051 nonn %O A258051 1,5 %A A258051 _Clark Kimberling_ and _Reinhard Zumkeller_, May 17 2015