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 A125756 #4 Mar 30 2012 17:21:02 %S A125756 4,36,140,145,200,292,1059,1136,1553,1800,2340,4150,4274,4297,4308, %T A125756 4389,4433,4490,4634,4696,4705,4741,4804,4876,5133,5164,5218,5254, %U A125756 5400,5409,5668,5712,5761,6244,6290,6312,6448,6466,6662,6800,6976 %N A125756 Numbers n whose reverse binary representation has the following property: let a 0 mean "halving" and a 1 mean "k -> 3k+1". The number describes an operation k -> f_n(k). If the equation f_n(k) = k has a positive integer solution, n is a term in the sequence. %C A125756 Suggested by A125626. %C A125756 Note that f_n(x) is always a linear function of x. %H A125756 David Applegate, <a href="/A125756/b125756.txt">Table of n, a(n) for n = 1..60</a> %Y A125756 Cf. A125626, A125755, A125754, A125757, A125710, A125711. %K A125756 nonn %O A125756 1,1 %A A125756 _David Applegate_, Feb 02 2007