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 A226686 #8 Jun 18 2013 12:36:01 %S A226686 11,17,19,34,69,84,85,168,171,176,179,228,252,285 %N A226686 Conjectured record-breaking lengths, for ascending positive integers k, of primitive cycles of positive integers under iteration by the Collatz-like 3x-k function. %C A226686 A cycle is called primitive if its elements are not a common multiple of the elements of another cycle. %C A226686 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. %C A226686 For primitive cycles, GCD(k,6)=1. %Y A226686 k = A226687(n). The smallest integer in the T_k cycle(s) associated with a(n) is A226688(n). %Y A226686 Cf. A226625, A226670. %K A226686 nonn %O A226686 1,1 %A A226686 _Geoffrey H. Morley_, Jun 16 2013