A180831 Number of distinct solutions of sum{i=1..8}(x(2i-1)*x(2i)) = 1 (mod n), with x() only in 2..n-2

0, 0, 0, 0, 9, 166, 3474, 36866, 345458, 2263066, 13182593, 61265760, 260084494, 944238967, 3208593348, 9709481260, 27970062531, 73672570068, 187003944842, 441746651920, 1014700253185, 2196105354893, 4653016292528, 9374868346319

Offset

1,5

Comments

Column 8 of A180834

Links

R. H. Hardin, Table of n, a(n) for n=1..183

Example

Solutions for sum of products of 8 2..3 pairs = 1 (mod 5) are
(2*2 + 2*2 + 2*2 + 2*2 + 2*2 + 2*2 + 2*3 + 2*3)
(2*2 + 2*2 + 2*2 + 2*2 + 2*2 + 2*3 + 2*3 + 3*3)
(2*2 + 2*2 + 2*2 + 2*2 + 2*3 + 2*3 + 3*3 + 3*3)
(2*2 + 2*2 + 2*2 + 2*3 + 2*3 + 3*3 + 3*3 + 3*3)
(2*2 + 2*2 + 2*3 + 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*3)
(2*2 + 2*3 + 2*3 + 3*3 + 3*3 + 3*3 + 3*3 + 3*3)
(2*3 + 2*3 + 2*3 + 2*3 + 2*3 + 2*3 + 2*3 + 3*3)
(2*3 + 2*3 + 3*3 + 3*3 + 3*3 + 3*3 + 3*3 + 3*3)

Crossrefs

Sequence in context: A166180 A376174 A004107 * A361094 A367135 A367139

Adjacent sequences: A180828 A180829 A180830 * A180832 A180833 A180834

Keyword

nonn

Author

R. H. Hardin Sep 20 2010

Status

approved