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 A226673 #4 Jun 20 2013 14:28:19 %S A226673 1,17,18,26,41,56,74,80,89,115,126,142,215,220,256,311,387,1000,1136, %T A226673 1146,2253,2292,2590,2937,4971,5326,7157,8294,9920,18862,20429,24842, %U A226673 31913 %N A226673 Conjectured record-breaking numbers of odd elements, for ascending positive integers k, in primitive cycles of positive integers under iteration by the Collatz-like 3x+k function. %C A226673 A cycle is called primitive if its elements are not a common multiple of the elements of another cycle. %C A226673 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 A226673 For primitive cycles, GCD(k,6)=1. %Y A226673 k = A226674(n). The smallest integer in the T_k cycle associated with a(n) is A226675(n). %Y A226673 Cf. A226610, A226689. %K A226673 nonn %O A226673 1,2 %A A226673 _Geoffrey H. Morley_, Jun 19 2013