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 A028395 #25 Mar 01 2019 08:04:35
%S A028395 14,21,16,24,36,54,81,61,46,69,52,78,117,88,132,198,297,223,167,125,
%T A028395 94,141,106,159,119,89,67,50,75,56,84,126,189,142,213,160,240,360,540,
%U A028395 810,1215,911,683,512,768,1152,1728,2592,3888,5832,8748,13122,19683
%N A028395 Iterate the map in A006368 starting at 14.
%H A028395 T. D. Noe, <a href="/A028395/b028395.txt">Table of n, a(n) for n = 0..1000</a>
%H A028395 J. H. Conway, <a href="http://www.jstor.org/stable/10.4169/amer.math.monthly.120.03.192">On unsettleable arithmetical problems</a>, Amer. Math. Monthly, 120 (2013), 192-198.
%H A028395 D. Gale, <a href="http://dx.doi.org/10.1007/978-1-4612-2192-0">Tracking the Automatic Ant And Other Mathematical Explorations</a>, A Collection of Mathematical Entertainments Columns from The Mathematical Intelligencer, Springer, 1998; see p. 16.
%H A028395 <a href="/index/3#3x1">Index entries for sequences related to 3x+1 (or Collatz) problem</a>
%F A028395 a(n+1) = A006368(a(n)).
%t A028395 SubstitutionSystem[{n_ :> If[EvenQ[n], 3n/2, Round[3n/4]]}, {14}, 60] // Flatten (* _Jean-François Alcover_, Mar 01 2019 *)
%o A028395 (Haskell)
%o A028395 a028395 n = a028395_list !! n
%o A028395 a028395_list = iterate a006368 14 -- _Reinhard Zumkeller_, Apr 18 2012
%Y A028395 Cf. A028393.
%Y A028395 Cf. A180853, A180864, A182205; A028398(5) = 14.
%K A028395 nonn
%O A028395 0,1
%A A028395 _J. H. Conway_