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A356758
a(n) is the number of nonzero digits in n!.
3
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, 20, 24, 24, 27, 26, 29, 28, 32, 32, 32, 29, 35, 39, 35, 39, 40, 43, 44, 42, 49, 48, 49, 46, 49, 50, 53, 54, 56, 58, 57, 62, 62, 63, 58, 66, 67, 70, 71, 70, 73, 72, 78, 81
OFFSET
0,5
FORMULA
a(n) = A034886(n!) - A027869(n!).
MATHEMATICA
Table[Length[Select[IntegerDigits[n!], Positive]], {n, 0, 70}]
PROG
(PARI) a(n) = #select(x->(x>0), digits(n!)); \\ Michel Marcus, Aug 26 2022
(Python)
from math import factorial
def a(n): return len(str(factorial(n)).replace("0", ""))
print([a(n) for n in range(71)]) # Michael S. Branicky, Aug 26 2022
CROSSREFS
KEYWORD
easy,base,nonn
AUTHOR
Stefano Spezia, Aug 26 2022
STATUS
approved