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 A061523 #10 May 02 2018 12:49:58
%S A061523 1,5,7,10,341,356,701,1600,1776,2806,3994,9729,20224,21891,107860,
%T A061523 115180,131346,204765,221646,284348,426522,748056,9099150,15596837,
%U A061523 27297444,30359613,4422186001
%N A061523 Integer part of the blowup factor for A025587(n).
%e A061523 a(4)=10 since A025587(4)=15 and starting with 15 in the Collatz sequence gives a maximum value of 160 with a blowup factor of 160/15 = 10.66666...
%t A061523 With[{s = Array[Max@ NestWhileList[If[EvenQ@ #, #/2, 3 # + 1] &, #, # > 1 &]/# &, 2^18]}, Floor@ Union@ FoldList[Max, s]] (* _Michael De Vlieger_, Mar 13 2018 *)
%Y A061523 Cf. A025587, A295163.
%K A061523 nonn
%O A061523 0,2
%A A061523 Larry Reeves (larryr(AT)acm.org), May 03 2001