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 A222597 #8 Aug 26 2016 23:31:21
%S A222597 0,0,5,0,2,3,12,0,13,1,8,1,3,8,11,0,4,7,10,0,2,4,7,0,10,1,102,3,5,8,
%T A222597 97,0,10,2,5,2,4,5,17,0,97,1,10,1,3,5,92,0,5,4,7,0,2,95,98,0,9,1,11,4,
%U A222597 6,91,93,0,5,3,6,0,2,3,87,0,97,1,7,1,3,10,13,0,6
%N A222597 Number of terms of the Collatz (3x+1) trajectory of n that are greater than n.
%H A222597 T. D. Noe, <a href="/A222597/b222597.txt">Table of n, a(n) for n = 1..10000</a>
%t A222597 Collatz[n_] := NestWhileList[If[EvenQ[#], #/2, 3 # + 1] &, n, # > 1 &]; Table[Length[Select[Collatz[n], # > n &]], {n, 100}]
%o A222597 (PARI) a(n)=my(k=n,s); while(k>1, k=if(k%2,3*k+1,k/2); if(k>n,s++)); s \\ _Charles R Greathouse IV_, Aug 26 2016
%Y A222597 Cf. A033496, A213199 (location of zero and nonzero terms).
%K A222597 nonn
%O A222597 1,3
%A A222597 _T. D. Noe_, Mar 01 2013