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 A226663 #11 Jun 27 2013 12:07:24 %S A226663 1,5,9,19,20,23,52,53,97,142,534,944,950,3806,4782 %N A226663 Conjectured record-breaking numbers, for ascending positive integers k, of primitive cycles of positive integers under iteration by the Collatz-like 3x+k function. %C A226663 A cycle is called primitive if its elements are not a common multiple of the elements of another cycle. %C A226663 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 A226663 For primitive cycles, GCD(k,6)=1. %H A226663 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). %H A226663 E. G. Belaga and M. Mignotte, <a href="http://hal.archives-ouvertes.fr/hal-00129726">Walking Cautiously into the Collatz Wilderness: Algorithmically, Number Theoretically, Randomly</a>, Fourth Colloquium on Mathematics and Computer Science, DMTCS proc. AG. (2006), 249-260. %H A226663 E. G. Belaga and M. Mignotte, <a href="http://hal.archives-ouvertes.fr/hal-00129727">The Collatz Problem and Its Generalizations: Experimental Data. Table 1. Primitive Cycles of (3n+d)-mappings</a>, Preprint math. 2006/15, Univ. Louis Pasteur, Strasbourg (2006). %Y A226663 k = A226664(n). %Y A226663 Cf. A226613, A226679. %K A226663 nonn %O A226663 1,2 %A A226663 _Geoffrey H. Morley_, Jun 15 2013