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 A226606 #8 Apr 06 2020 20:11:11
%S A226606 1,1,1,1,5,11,7,13,49,5,5,23,23,29,179,17,17,37,37,37,11,55,61,601,
%T A226606 115,115,47,115,47,47,101,47,47,101,101,101,119,101,17,119,125,1931,
%U A226606 473,473,13,473,13,13,35,13,13,175,13,175,175,229,13,35,175,25,229
%N A226606 Irregular array read by rows in which a(n) is the denominator of the rational number, in a 3x+1 cycle, with numerator A226605(n).
%H A226606 Geoffrey H. Morley, <a href="/A226606/b226606.txt">Rows 1..16 of array, flattened</a>
%H A226606 See A226605 for other link(s).
%F A226606 If v(0) to v(m-1) are the bits of A102659(n), when 2's are replaced by 0's, then a(n) = D(n)/GCD(N(n),D(n)) where D(n) = 2^m - 3^(v(0)+...+v(m-1)) and N(n) = Sum_{j=0 to m-1} (2^j)(3^(v(j+1)+...+v(m-1)))v(j).
%K A226606 nonn,frac,tabf
%O A226606 1,5
%A A226606 _Geoffrey H. Morley_, Jun 27 2013