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 A272697 #30 Sep 04 2024 20:04:36
%S A272697 1,16,32,128,256,1024,4096,262144,524288,8388608
%N A272697 Powers of 2 with exactly one odd decimal digit.
%C A272697 Inspired by A068994 (Powers of 2 such that number of odd digits is 0).
%C A272697 No additional terms up to 2^10000.
%C A272697 No additional terms < 2^500000. - _Chai Wah Wu_, May 22 2016
%C A272697 No additional terms < 2^(10^10). - _Michael S. Branicky_, Apr 16 2023
%t A272697 Select[2^Range[0, 50000], Total@ Pick[DigitCount@ #, {1, 0, 1, 0, 1, 0, 1, 0, 1, 0}, 1] == 1 &] (* _Michael De Vlieger_, May 04 2016 *)
%t A272697 od1Q[n_]:=Count[IntegerDigits[n],_?(OddQ[#]&)]==1; Select[2^Range[0,100],od1Q] (* _Harvey P. Dale_, Sep 04 2024 *)
%o A272697 (Ruby)
%o A272697 ary = [1]
%o A272697 s = 1
%o A272697 (1..10 ** 4).each{|i|
%o A272697 s *= 2
%o A272697 j = s.to_s.split('').map(&:to_i).select{|i| i % 2 == 1}.size
%o A272697 ary << s if j == 1
%o A272697 }
%o A272697 p ary
%Y A272697 Cf. A068994, A272698.
%K A272697 nonn,base
%O A272697 1,2
%A A272697 _Seiichi Manyama_, May 04 2016