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 A226620 #5 Jul 04 2013 21:16:50 %S A226620 1,0,1,2,1,3,2,1,4,3,2,1,5,4,2,3,2,1,6,5,2,4,3,2,1,7,6,5,4,4,4,3,2,1, %T A226620 8,7,6,6,3,5,4,3,2,1,9,8,7,8,6,5,2,2,6,5,4,3,2,1,10,9,8,7,7,5,3,5,4,5, %U A226620 6,5,4,3,2,1,11,10,9,8,9,8,8,8,8,4,4,7 %N A226620 Irregular array read by rows in which a(n) is the number of odd elements in each primitive '3x+k' cycle associated with A226619(n). %C A226620 The terms in row n are associated with cycles of length n (see A226619). %H A226620 Geoffrey H. Morley, <a href="/A226620/b226620.txt">Rows 1..26 of array, flattened</a> %e A226620 The irregular array starts: %e A226620 1, 0; %e A226620 1; %e A226620 2, 1; %e A226620 3, 2, 1; %e A226620 4, 3, 2, 1; %e A226620 5, 4, 2, 3, 2, 1; ... %Y A226620 Cf. A226621. %K A226620 nonn,tabf %O A226620 1,4 %A A226620 _Geoffrey H. Morley_, Jul 02 2013