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%I #19 Aug 10 2024 21:39:05
%S 1,1,1,1,2,2,2,2,3,5,5,6,5,6,9,9,10,11,11,12,12,13,14,18,18,17,19,20,
%T 20,24,24,27,26,29,28,32,32,32,29,35,39,35,39,40,43,44,42,49,48,49,46,
%U 49,50,53,54,56,58,57,62,62,63,58,66,67,70,71,70,73,72,78,81
%N a(n) is the number of nonzero digits in n!.
%H Robert G. Wilson v, <a href="/A356758/b356758.txt">Table of n, a(n) for n = 0..10000</a>
%H <a href="/index/Fa#factorial">Index entries for sequences related to factorial numbers</a>
%F a(n) = A034886(n!) - A027869(n!).
%t Table[Length[Select[IntegerDigits[n!],Positive]],{n,0,70}]
%o (PARI) a(n) = #select(x->(x>0), digits(n!)); \\ _Michel Marcus_, Aug 26 2022
%o (Python)
%o from math import factorial
%o def a(n): return len(str(factorial(n)).replace("0", ""))
%o print([a(n) for n in range(71)]) # _Michael S. Branicky_, Aug 26 2022
%Y Cf. A000142, A027869, A034886, A356757.
%K easy,base,nonn
%O 0,5
%A _Stefano Spezia_, Aug 26 2022