|
%I #19 Sep 21 2022 08:52:41
%S 1,2,2,3,2,4,2,4,3,4,2,6,2,4,4,5,2,6,2,6,4,4,2,8,3,4,4,6,2,8,2,6,4,4,
%T 4,9,2,4,4,8,2,8,2,6,6,4,2,10,3,6,4,6,2,8,4,8,4,4,2,12,2,4,6,7,4,8,2,
%U 6,4,8,2,12,2,4,6,6,4,8,2,10,5,4,2,12,4,4,4,8,2,12,4,6,4,4,4,12,2,6,6,9
%N Number of times n appears in a 1000 X 1000 multiplication table.
%C Identical to A000005(n), the number of divisors of n, for n <= 1000.
%C As the size of the multiplication table grows, sequences of this kind approach A000005: the number of divisors of n. Any term becomes stable once the size equals or exceeds n. - _Robert G. Wilson v_, Aug 03 2010
%H T. D. Noe, <a href="/A179942/b179942.txt">Table of n, a(n) for n = 1..10000</a>
%F a(n) = 0 for n > 10^6.
%e a(2)=2 because the number 2 appears in 2 cells in a 1000 X 1000 multiplication table.
%t nn = 1000; mtab = Flatten[Table[i*j, {i, nn}, {j, nn}]]; Table[Count[mtab, n], {n, 10000}]
%o (PARI) a(n)=sumdiv(n,d,d<1001 && n/d<1001) \\ _Charles R Greathouse IV_, Dec 27 2016
%Y Cf. A179940, A179941.
%K nonn,fini,less
%O 1,2
%A _Dominick Cancilla_, Aug 02 2010
%E Observations rephrased as facts by _R. J. Mathar_, Aug 03 2010
|
