%I A034886
%S A034886 1,1,1,1,2,3,3,4,5,6,7,8,9,10,11,13,14,15,16,18,19,20,22,23,24,26,27,
%T A034886 29,30,31,33,34,36,37,39,41,42,44,45,47,48,50,52,53,55,57,58,60,62,63,
%U A034886 65,67,68,70,72,74,75,77,79,81,82,84,86,88,90,91,93,95,97,99,101,102
%N A034886 Number of digits in n!.
%H A034886 <a href="Sindx_Fa.html#factorial">Index entries for sequences related 
               to factorial numbers</a>.
%H A034886 Wikipedia, <a href="http://en.wikipedia.org/wiki/Stirling's_approximation">
               Stirling's Formula</a>.
%F A034886 a(n) = floor(log(n!)/log(10)) + 1
%F A034886 a(n) = A027869(n) + A079680(n) + A079714(n) + A079684(n) + A079688(n) 
               + A079690(n) + A079691(n) + A079692(n) + A079693(n) + A079694(n); 
               a(n) = A055642(A000142(n)). - Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), 
               Jan 27 2008
%F A034886 Using Stirling's formula we can derive a formula, which is very fast 
               to compute in practice: floor((log(2*pi*n)/2+n*(log(n)-log(e)))/log(10))+1. 
               - Dmitry Kamenetsky (dkamen(AT)rsise.anu.edu.au), Jul 07 2008
%p A034886 [ seq(length(n!), n=0..100) ];
%p A034886 seq(length((n)!), n=0..71); - Zerinvary Lajos (zerinvarylajos(AT)yahoo.com), 
               Mar 10 2007
%Y A034886 Sequence in context: A101788 A024698 A011883 this_sequence A011882 A025767 
               A091848
%Y A034886 Adjacent sequences: A034883 A034884 A034885 this_sequence A034887 A034888 
               A034889
%K A034886 nonn,base,easy
%O A034886 0,5
%A A034886 Erich Friedman (erich.friedman(AT)stetson.edu)