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 A270570 #23 Apr 12 2016 11:50:22
%S A270570 1,16,2,16,16,52,4,52,16,52,16,40,52,160,8,52,52,88,16,64,52,160,16,
%T A270570 88,40,9232,52,88,160,9232,16,100,52,160,52,112,88,304,20,9232,64,196,
%U A270570 52,136,160,9232,24,148,88,232,40,160,9232,9232,52,196,88,304,160
%N A270570 Largest number in the sequence for the Collatz problem (excluding the original number) when started at n.
%H A270570 Robert Price, <a href="/A270570/b270570.txt">Table of n, a(n) for n = 2..10000</a>
%e A270570 For n = 7, the sequence is: 7, 22, 11, 34, 17, *52*, 26, 13, 40, 20, 10, 5, 16, 8, 4, 2, 1. The highest value in the list (starred) is 52.
%t A270570 Table[k = n; maxk = 0; While[k ≠ 1, If[EvenQ[k], k = k/2, k = 3*k + 1]; maxk = Max[maxk, k]]; maxk, {n, 2, 100}] (* _Robert Price_, Apr 11 2016 *)
%K A270570 nonn
%O A270570 2,2
%A A270570 _Douglas Boffey_, Mar 19 2016