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 A378833 #8 Dec 12 2024 18:23:44 %S A378833 0,0,1,0,0,1,1,0,4,0,1,1,3,1,2,0,0,4,2,0,3,1,1,1,6,3,1,1,2,2,2,0,7,0, %T A378833 4,4,5,2,3,0,3,3,1,1,8,1,5,1,6,6,3,3,4,1,4,1,9,2,2,2,2,2,6,0,12,7,7,0, %U A378833 5,4,5,4,5,5,2,2,3,3,3,0,7,3,3,3,8,1,13 %N A378833 Number of tripling steps in the 3x-1 trajectory from n to the minimum of its cycle, or -1 if n never reaches a cycle. %C A378833 The 3x-1 iteration is x -> 3x-1 if x odd, or x -> x/2 if x even (A001281). %C A378833 The cycle minima presently known are 1, 5 and 17. %C A378833 a(n) = 0 iff n = m*2^k where m is one of the cycle minima. %H A378833 Kevin Ryde, <a href="/A378833/b378833.txt">Table of n, a(n) for n = 1..10000</a> %F A378833 a(n) = A135730(n) - A377524(n), if a(n) != -1. %Y A378833 Cf. A001281 (step), A135730 (total steps), A377524 (halving steps). %K A378833 nonn,easy %O A378833 1,9 %A A378833 _Kevin Ryde_, Dec 08 2024