%I #8 Apr 26 2021 15:25:09
%S 1,0,0,1,1,0,0,0,3,1,1,1,4,1,1,1,4,2,2,1,5,2,4,1,3,3,11,1,4,4,2,6,5,2,
%T 5,8,5,3,7,5,9,8,7,12,5,5,8,7,7,6,16,14,7,12,11,7,12,6,10,13,7,14,12,
%U 16,11,14,10,14,11,22,12,10,27,19,18,6,17,18,16,13,16,19,16,12,20,21,12,21
%N Number of 2's in n# (n primorial) = 2's in A002110(n).
%H Vincenzo Librandi, <a href="/A079110/b079110.txt">Table of n, a(n) for n = 2..1000</a>
%t DigitCount[#, 10, 2]&/@Rest[FoldList[Times, 1, Prime[Range[100]]]] (* _Vincenzo Librandi_, Apr 07 2014 *)
%o (PARI) See program in Number of 0's in n#
%Y Cf. A002110.
%K nonn,base,easy
%O 2,9
%A _Cino Hilliard_, Feb 03 2003