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 A028396 #16 Mar 01 2019 08:04:26
%S A028396 14,19,25,33,22,29,39,26,35,47,63,42,28,37,49,65,87,58,77,103,137,183,
%T A028396 122,163,217,289,385,513,342,228,152,203,271,361,481,641,855,570,380,
%U A028396 507,338,451,601,801,534,356,475,633,422,563,751,1001,1335,890,1187
%N A028396 Iterate the map in A006369 starting at 14.
%H A028396 T. D. Noe, <a href="/A028396/b028396.txt">Table of n, a(n) for n = 0..1000</a>
%H A028396 <a href="/index/3#3x1">Index entries for sequences related to 3x+1 (or Collatz) problem</a>
%t A028396 SubstitutionSystem[{n_ :> Switch[Mod[n, 3], 0, 2n/3, 1, (4n - 1)/3, _, (4n + 1)/3]}, {14}, 60] // Flatten (* _Jean-François Alcover_, Mar 01 2019 *)
%o A028396 (Haskell)
%o A028396 a028396 n = a028396_list !! n
%o A028396 a028396_list = iterate a006369 14 -- _Reinhard Zumkeller_, Dec 31 2011
%Y A028396 Cf. A028394, A028396, A094328, A094329, A185589, A185590.
%K A028396 nonn
%O A028396 0,1
%A A028396 _J. H. Conway_