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 A226670 #14 Jun 27 2013 12:06:05 %S A226670 2,27,31,43,65,66,100,106,118,136,140,141,162,200,222,262,426,476,526, %T A226670 636,737,1922,2254,4531,4686,5194,5945,9946,10702,14219,16340,19904, %U A226670 37582,40983,49711,63330 %N A226670 Record-breaking values, for increasing positive integers k == 1 or 5 mod 6, of the conjectured length of the longest primitive cycle(s) of positive integers under iteration by the Collatz-like 3x+k function. %C A226670 A cycle is called primitive if its elements are not a common multiple of the elements of another cycle. %C A226670 The 3x+k function T_k is defined by T_k(x) = x/2 if x is even, (3x+k)/2 if x is odd, where k is odd. %C A226670 For primitive cycles, GCD(k,6)=1. %H A226670 E. G. Belaga and M. Mignotte, <a href="http://hal.archives-ouvertes.fr/hal-00129656">Cyclic Structure of Dynamical Systems Associated with 3x+d Extensions of Collatz Problem</a>, Preprint math. 2000/17, Univ. Louis Pasteur, Strasbourg (2000). %Y A226670 k = A226671(n). The smallest integer in the T_k cycle(s) associated with a(n) is A226672(n). %Y A226670 Cf. A226609, A226686. %K A226670 nonn %O A226670 1,1 %A A226670 _Geoffrey H. Morley_, Jun 16 2013 %E A226670 Definition clarified by _Geoffrey H. Morley_, Jun 23 2013