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A180819
Number of distinct solutions of sum{i=1..7}(x(2i-1)*x(2i)) = 0 (mod n), with x() only in 2..n-2
1
0, 0, 0, 1, 9, 168, 1636, 16029, 98932, 566139, 2452576, 9997696, 33559251, 107928162, 302208130, 819882076, 1997861697, 4777963921, 10461759204, 22651681426, 45635928642, 91229866983, 171539771236, 322071749769
OFFSET
1,5
COMMENTS
Column 7 of A180823
LINKS
EXAMPLE
Solutions for sum of products of 7 2..3 pairs = 0 (mod 5) are
(2*2 + 2*2 + 2*2 + 2*2 + 2*2 + 2*2 + 2*3)
(2*2 + 2*2 + 2*2 + 2*2 + 2*2 + 2*3 + 3*3)
(2*2 + 2*2 + 2*2 + 2*2 + 2*3 + 3*3 + 3*3)
(2*2 + 2*2 + 2*2 + 2*3 + 3*3 + 3*3 + 3*3)
(2*2 + 2*2 + 2*3 + 3*3 + 3*3 + 3*3 + 3*3)
(2*2 + 2*3 + 2*3 + 2*3 + 2*3 + 2*3 + 2*3)
(2*2 + 2*3 + 3*3 + 3*3 + 3*3 + 3*3 + 3*3)
(2*3 + 2*3 + 2*3 + 2*3 + 2*3 + 2*3 + 3*3)
(2*3 + 3*3 + 3*3 + 3*3 + 3*3 + 3*3 + 3*3)
CROSSREFS
Sequence in context: A361094 A367135 A367139 * A132874 A223289 A281996
KEYWORD
nonn
AUTHOR
R. H. Hardin Sep 20 2010
STATUS
approved