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 A078565 #26 Mar 09 2023 18:15:21
%S A078565 0,0,1,1,3,3,6,7,10,13,11,19,17,21,25,23,27,27,30,40,40,41,42,44,51,
%T A078565 54,54,56,56,63,60,71,76,77,77,77,88,86,90,90,97,99,106,105,107,117,
%U A078565 115,117,114,122,126,130,138,138,151,144,146,157,160,158,160,176
%N A078565 Number of zeros in the binary expansion of n!.
%H A078565 T. D. Noe, <a href="/A078565/b078565.txt">Table of n, a(n) for n = 0..1000</a>
%F A078565 a(n) = A072831(n) - A079584(n). - _Michel Marcus_, Dec 23 2016
%e A078565 a(4) = 3 because 4! = 24_10 = 11000_2 and it has 3 zero digits.
%t A078565 Table[Count[IntegerDigits[n!, 2], 0], {n, 0, 100}] (* _T. D. Noe_, Apr 10 2012 *)
%t A078565 DigitCount[Range[0,70]!,2,0] (* _Harvey P. Dale_, Mar 11 2019 *)
%o A078565 (PARI) for(n=1,300,b=binary(n!); print1(sum(k=1,length(b),if(b[k],0,1))","))
%o A078565 (Python)
%o A078565 import math
%o A078565 def a(n):
%o A078565 return bin(math.factorial(n))[2:].count("0")
%o A078565 # _Indranil Ghosh_, Dec 23 2016
%Y A078565 Cf. A072831, A079584.
%K A078565 nonn,base
%O A078565 0,5
%A A078565 Jose R. Brox (tautocrona(AT)terra.es), Jan 26 2003