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 A213538 #10 Mar 04 2013 00:01:45
%S A213538 0,1,13,3,11,10,45,7,43,9,41,11,27,38,145,15,35,34,69,19,43,30,137,23,
%T A213538 63,25,9205,27,59,130,9201,31,67,33,125,35,75,50,265,39,9191,41,153,
%U A213538 43,91,114,9185,47,99,49,181,51,107,9178,9177,55,139,57,245,100,123
%N A213538 Maximum deviation from n in Collatz trajectory of n.
%C A213538 Assuming Collatz trajectory ends with 1 and also a(1)=0.
%H A213538 T. D. Noe, <a href="/A213538/b213538.txt">Table of n, a(n) for n = 1..10000</a>
%e A213538 a(3)=13 because the number furthest to 3 in Collatz trajectory of 3 is 16.
%t A213538 Collatz[n_] := NestWhileList[If[EvenQ[#], #/2, 3 # + 1] &, n, # > 1 &]; Join[{0}, Table[Max[Rest[Abs[Collatz[n] - n]]], {n, 2, 100}]] (* _T. D. Noe_, Mar 04 2013 *)
%Y A213538 Cf. A070165.
%K A213538 nonn
%O A213538 1,3
%A A213538 _Jayanta Basu_, Mar 03 2013