

A285387


Number of ordered (n+1)tuples of positive integers (s_1, s_2, ..., s_{n+1}) with s_(n+1)  s_n  ...  s_1 = s_(n+1)/(s_n * ... * s_1).


0



1, 3, 3, 7, 3, 6, 6, 6, 5, 9, 5, 12, 6, 6, 6, 11, 7, 12, 6, 11
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OFFSET

1,2


COMMENTS

a(n) >= 3 for n > 1: (1, ..., 1, 2, 2*(n+1)); (1, ..., 1, (n+1), 2*(n+1)) and (1, ..., 1, 2, n+1, 2*(n+1)) are always solutions.


LINKS

Table of n, a(n) for n=1..20.


EXAMPLE

For n=2, there are 3 solutions:
(1, 2, 6) is a solution since 6 / (2 * 1) = 3 = 6  2  1;
(1, 3, 6) is a solution since 6 / (3 * 1) = 2 = 6  3  1;
(2, 3, 6) is a solution since 6 / (3 * 2) = 1 = 6  3  2.


CROSSREFS

Sequence in context: A249806 A249382 A317929 * A100803 A036840 A159913
Adjacent sequences: A285384 A285385 A285386 * A285388 A285389 A285390


KEYWORD

nonn,more


AUTHOR

Reiner Moewald, Apr 18 2017


STATUS

approved



