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 A226123 #7 May 30 2013 11:03:17
%S A226123 1,2,5,3,5,5,5,4,5,5,5,5,5,5,5,5,5,5,5,5,7,5,5,5,5,5,5,5,5,5,5,6,5,5,
%T A226123 5,5,5,5,5,5,5,7,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,7,5,5,5,5,
%U A226123 5,5,5,5,5,5,9,5,5,5,5,5,5,5,5,7,9,5,5
%N A226123 Number of terms of the form 2^k in Collatz(3x+1) trajectory of n.
%C A226123 a(n) = sum(A209229(A070165(n,k)): k=1..A006577(n)). - _Reinhard Zumkeller_, May 30 2013
%H A226123 Reinhard Zumkeller, <a href="/A226123/b226123.txt">Table of n, a(n) for n = 1..10000</a>
%e A226123 a(3)=5 since Collatz trajectory of 3 contains terms 1,2,4,8 and 16.
%t A226123 coll[n_]:=NestWhileList[If[EvenQ[#],#/2,3#+1]&,n,#>1&]; Table[Length[Select[coll[n],IntegerQ[Log[2,#]]&]],{n,87}]
%o A226123 (Haskell)
%o A226123 a226123 = sum . map a209229 . a070165_row
%o A226123 -- _Reinhard Zumkeller_, May 30 2013
%Y A226123 Cf. A070165.
%Y A226123 Cf. A135282, A208981.
%K A226123 nonn
%O A226123 1,2
%A A226123 _Jayanta Basu_, May 27 2013