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 A198593 #6 Mar 30 2012 17:23:03
%S A198593 43,87,89,173,177,179,349,355,357,385,423,693,705,709,717,729,761,769,
%T A198593 771,777,847,1393,1397,1411,1415,1421,1429,1457,1459,1465,1481,1523,
%U A198593 1539,1541,1547,1555,1569,1689,1693,1697,2773,2787,2801,2821,2831,2837,2869
%N A198593 Odd numbers producing 10 odd numbers in the Collatz iteration.
%H A198593 T. D. Noe, <a href="/A198593/b198593.txt">Table of n, a(n) for n = 1..1000</a>
%t A198593 Collatz[n_] := NestWhileList[If[EvenQ[#], #/2, 3 # + 1] &, n, # > 1 &]; t = {}; Do[If[Length[Select[Collatz[n], OddQ]] == 10, AppendTo[t, n]], {n, 1, 10000, 2}]; t
%Y A198593 Cf. A198584.
%K A198593 nonn
%O A198593 1,1
%A A198593 _T. D. Noe_, Oct 31 2011