%I #58 Sep 24 2019 02:45:33
%S 1,1,2,6,2,1,7,5,4,3,3,3,4,6,8,1,2,3,6,1,2,5,1,2,6,1,4,1,3,8,2,8,2,8,
%T 2,1,3,1,5,2,8,3,1,6,2,1,5,2,1,6,3,1,8,4,2,1,7,4,2,1,8,5,3,1,1,8,5,3,
%U 2,1,1,8,6,4,3,2,1,1,1,8,7,5,4,3,3,2,2,2,1,1,1,1,1,1,1,1,9,9,9,9,9,9,9,9,1
%N Leading digit of n!.
%C Kunoff proved that the distribution of terms of this sequence follows Benford's law, i.e., the asymptotic density of terms with value d (between 1 and 9) is log_10(1+1/d). - _Amiram Eldar_, Sep 23 2019
%H Seiichi Manyama, <a href="/A008905/b008905.txt">Table of n, a(n) for n = 0..10000</a> (terms 0..1000 from T. D. Noe)
%H Sharon Kunoff, <a href="https://www.fq.math.ca/Scanned/25-4/kunoff.pdf">N! has the first digit property</a>, The Fibonacci Quarterly, Vol. 25, No. 4 (1987), pp. 365-367.
%H <a href="/index/Fa#factorial">Index entries for sequences related to factorial numbers</a>
%F a(n) = A000030(A000142(n)). - _Reinhard Zumkeller_, Apr 08 2012
%t f[n_] := Quotient[n!, 10^Floor@ Log[10, n!]]; Array[f, 105, 0]
%o (Haskell)
%o a008905 = a000030 . a000142 -- _Reinhard Zumkeller_, Apr 08 2012
%Y Cf. A000966, A000142, A018799, A202021 (leading digit of (10^n)!), A213201.
%K nonn,base,easy
%O 0,3
%A _Russ Cox_
%E Two less-efficient Mathematica codings removed by _Robert G. Wilson v_, Nov 05 2010
|