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 A254637 #5 Feb 03 2015 21:11:23
%S A254637 2,16,2,192,128,32768,4,69632,23552,25722880,425984,717895680,
%T A254637 1051828224,217079873536,8,2270641389568,10603200512,156423849771008,
%U A254637 950175531008,25160124578398208,385584983965696,450589122059304960,40722497536,53279734579488838656
%N A254637 Maximal element of Image^inf({ 2 }) under repeated base-n zero-split doubling.
%C A254637 Define f_b(x) to be the set of base b numbers left after splitting 2x at its zero digits and Image_b(S) = union_{x in S}{ { x } union f_b(S) }, then a(n) = max(Image_n^inf({ 2 }))
%H A254637 Hugo van der Sanden, <a href="/A254637/b254637.txt">Table of n, a(n) for n = 2..62</a>
%H A254637 Hugo van der Sanden, <a href="https://github.com/hvds/seq/tree/master/zerofree">Perl and C implementations</a>, Feb 03 2015
%e A254637 a(8) = 4 since f_8(2) = { 4 }, f_8(4) = { 1 }, f_8(1) = { 2 } so Image_8^inf({ 2 }) = { 1, 2, 4 }.
%Y A254637 Cf A254638, A113917
%K A254637 nonn,easy
%O A254637 2,1
%A A254637 _Hugo van der Sanden_, Feb 03 2015