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 A065717 #28 Apr 25 2020 13:32:55
%S A065717 0,0,0,0,1,0,1,0,1,0,0,0,1,0,1,1,2,0,1,0,1,0,0,1,2,0,2,0,2,1,0,1,2,0,
%T A065717 1,1,3,0,1,0,2,0,1,1,2,0,3,0,3,1,2,1,2,0,0,3,1,0,1,2,4,1,3,1,3,1,4,2,
%U A065717 1,1,1,3,6,1,1,3,2,2,3,2,4,1,2,4,3,6,3,2,2,4,0,1,4,0,3,4,3,3,2,3,5
%N A065717 Number of 6's in decimal expansion of 2^n.
%H A065717 Harry J. Smith, <a href="/A065717/b065717.txt">Table of n, a(n) for n = 0..1000</a>
%e A065717 2^8 = 256 so a(8)=1.
%t A065717 Table[ Count[ IntegerDigits[2^n], 6], {n, 0, 100} ]
%t A065717 DigitCount[#,10,6]&/@(2^Range[0,100]) (* _Harvey P. Dale_, Feb 15 2020 *)
%o A065717 (PARI) a(n) = #select(x->(x==6), digits(2^n)); \\ _Andrew Howroyd_, Apr 25 2020
%o A065717 (Python)
%o A065717 def A065717(n):
%o A065717 return str(2**n).count('6') # _Chai Wah Wu_, Feb 14 2020
%Y A065717 Cf. 0's A027870, 1's A065712, 2's A065710, 3's A065714, 4's A065715, 5's A065716, 7's A065718, 8's A065719, 9's A065744.
%K A065717 nonn,base
%O A065717 0,17
%A A065717 _Benoit Cloitre_, Dec 04 2001
%E A065717 More terms from _Robert G. Wilson v_, Dec 07 2001