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Number of ways to write n as a product with all factors <= n/5.
7

%I #6 Jul 13 2013 12:04:31

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

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

%U 0,3,0,11,0,0,2,0,1,2,0,8,3,0,0,6,1,0

%N Number of ways to write n as a product with all factors <= n/5.

%C a(n) = A066032(n,floor(n/5)) for n > 4.

%H Reinhard Zumkeller, <a href="/A216601/b216601.txt">Table of n, a(n) for n = 1..1000</a>

%e a(50) = #{10*2, 5*5*2} = 2;

%e a(51) = #{} = 0;

%e a(52) = #{} = 0;

%e a(53) = #{} = 0;

%e a(54) = #{9*6, 9*3*2, 6*3*3, 3*3*3*2} = 4;

%e a(55) = #{11*5} = 1.

%o (Haskell)

%o a216601 n | n <= 4 = 0

%o | otherwise = a066032_tabl !! (n-1) !! (n `div` 5 - 1)

%Y Cf. A001055, A028422, A216599, A216600, A216602.

%K nonn

%O 1,24

%A _Reinhard Zumkeller_, Oct 01 2012