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Number of ways to write n as a product with all factors <= n/4.
7

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

%S 0,0,0,0,0,0,0,1,0,0,0,1,0,0,0,3,0,1,0,2,0,0,0,4,1,0,1,2,0,2,0,5,0,0,

%T 1,6,0,0,0,5,0,2,0,2,2,0,0,9,1,2,0,2,0,4,1,5,0,0,0,8,0,0,2,9,1,2,0,2,

%U 0,3,0,13,0,0,2,2,1,2,0,10,3,0,0,8,1,0

%N Number of ways to write n as a product with all factors <= n/4.

%C a(n) = A066032(n,floor(n/4)) for n > 3.

%H Reinhard Zumkeller, <a href="/A216600/b216600.txt">Table of n, a(n) for n = 1..1000</a>

%e a(40) = #{10*4, 10*2*2, 8*5, 5*4*2, 5*2*2*2} = 5;

%e a(41) = #{} = 0;

%e a(42) = #{7*6, 7*3*2} = 2;

%e a(43) = #{} = 0;

%e a(44) = #{11*4, 11*2*2} = 2;

%e a(45) = #{9*5, 5*3*3} = 2.

%o (Haskell)

%o a216600 n | n <= 3 = 0

%o | otherwise = a066032_tabl !! (n-1) !! (n `div` 4 - 1)

%Y Cf. A001055, A028422, A216599, A216601, A216602.

%K nonn

%O 1,16

%A _Reinhard Zumkeller_, Oct 01 2012