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%I #15 Aug 20 2017 12:53:10
%S 2,4,8,16,32,512
%N Powers of 2 with exactly one even decimal digit.
%C The number of even digits of powers of 2 is more than 0. However, it seems there are few powers of 2 with 1 even digit.
%C If there are any other terms in this sequence, they are greater than 2^10^10. - _Charles R Greathouse IV_, May 04 2016
%t Select[2^Range[0, 50000], Total@ Pick[DigitCount@ #, {0, 1, 0, 1, 0, 1, 0, 1, 0, 1}, 1] == 1 &] (* _Michael De Vlieger_, May 04 2016 *)
%t Select[2^Range[200],Count[IntegerDigits[#],_?EvenQ]==1&] (* _Harvey P. Dale_, Aug 20 2017 *)
%o (Ruby)
%o ary = []
%o s = 1
%o (1..10 ** 4).each{|i|
%o s *= 2
%o j = s.to_s.split('').map(&:to_i).select{|i| i % 2 == 0}.size
%o ary << s if j == 1
%o }
%o p ary
%o (PARI) is(n)=my(d=digits(n)); n>1 && n>>valuation(n,2)==1 && sum(i=1,#d,d[i]%2==0)==1 \\ _Charles R Greathouse IV_, May 04 2016
%K nonn,base
%O 1,1
%A _Seiichi Manyama_, May 04 2016
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