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 A171813 #4 Mar 30 2016 12:09:16
%S A171813 1,101,734,1037,1174,1165,1165,1165,1165,1165,1165,1165,1165,1165,
%T A171813 1165,1165,1165,1165,1165,1165,1165,1165,1165,1165,1165,1165,1165,
%U A171813 1165,1165,1165,1165,1165,1165,1165,1165,1165,1165,1165,1165,1165
%N A171813 Trajectory of 1 under repeated applications of the map i -> A171798(i).
%C A171813 Start with n, repeatedly apply the map i -> A171798(i). Then every n converges to one of 1019, 1147, 1165 or 14311. Proof: this is true by direct calculation for n=1..2^14. For larger n, A171798(n) < n.
%t A171813 ans[n_]:=Module[{idn2=IntegerDigits[n,2]},FromDigits[{Length[ idn2], Count[ idn2,0], Count[ idn2,1]}]]; NestList[ans,1,40] (* _Harvey P. Dale_, Mar 30 2016 *)
%Y A171813 Cf. A171798.
%K A171813 nonn,base
%O A171813 1,2
%A A171813 _N. J. A. Sloane_, Oct 15 2010, Oct 16 2010