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A216601 Number of ways to write n as a product with all factors <= n/5. 7
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, 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, 0, 3, 0, 11, 0, 0, 2, 0, 1, 2, 0, 8, 3, 0, 0, 6, 1, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,24

COMMENTS

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

LINKS

Reinhard Zumkeller, Table of n, a(n) for n = 1..1000

EXAMPLE

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

a(51) = #{} = 0;

a(52) = #{} = 0;

a(53) = #{} = 0;

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

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

PROG

(Haskell)

a216601 n | n <= 4    = 0

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

CROSSREFS

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

Sequence in context: A115604 A128617 A116488 * A283000 A145765 A157424

Adjacent sequences:  A216598 A216599 A216600 * A216602 A216603 A216604

KEYWORD

nonn

AUTHOR

Reinhard Zumkeller, Oct 01 2012

STATUS

approved

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Last modified August 20 22:45 EDT 2019. Contains 326155 sequences. (Running on oeis4.)