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Number of 9's in n!.
14

%I #16 Nov 02 2022 10:29:20

%S 0,0,0,0,0,0,0,0,0,0,0,2,1,0,1,0,2,1,0,0,1,3,0,1,2,2,1,1,0,4,2,1,2,2,

%T 5,3,7,4,1,5,5,0,4,2,2,4,6,7,3,2,2,3,3,6,4,6,6,5,6,8,6,7,6,7,5,6,6,8,

%U 8,7,12,5,7,5,7,10,12,7,6,9,5,12,13,12,10,9,9,10,13,18,14,12,7,7,7,15,20,16

%N Number of 9's in n!.

%H Seiichi Manyama, <a href="/A079694/b079694.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) + A079680(n) + A079714(n) + A079684(n) + A079688(n) + A079690(n) + A079691(n) + A079692(n) + A079693(n)). - _Reinhard Zumkeller_, Jan 27 2008

%t DigitCount[#,10,9]&/@(Range[0,100]!) (* _Harvey P. Dale_, Dec 12 2013 *)

%Y Cf. A027869, A079714.

%Y Cf. A000142, A137579, A137580.

%K nonn,base,easy

%O 0,12

%A _Cino Hilliard_, Jan 31 2003