A180821 Number of distinct solutions of sum{i=1..9}(x(2i-1)*x(2i)) = 0 (mod n), with x() only in 2..n-2

0, 0, 0, 1, 11, 409, 6946, 108997, 1113650, 9684748, 64448228, 375427744, 1820591506, 7980182839, 30660616489, 109065451832, 351179673979, 1065973101574, 2992063116800, 8019394451018, 20182278132284, 48949438473158

Offset

1,5

Comments

Column 9 of A180823

Links

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

Example

Solutions for sum of products of 9 2..3 pairs = 0 (mod 5) are
(2*2 + 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*2 + 2*3 + 2*3 + 3*3)
(2*2 + 2*2 + 2*2 + 2*2 + 2*2 + 2*3 + 2*3 + 3*3 + 3*3)
(2*2 + 2*2 + 2*2 + 2*2 + 2*3 + 2*3 + 3*3 + 3*3 + 3*3)
(2*2 + 2*2 + 2*2 + 2*3 + 2*3 + 3*3 + 3*3 + 3*3 + 3*3)
(2*2 + 2*2 + 2*3 + 2*3 + 2*3 + 2*3 + 2*3 + 2*3 + 2*3)
(2*2 + 2*2 + 2*3 + 2*3 + 3*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 + 3*3)
(2*2 + 2*3 + 2*3 + 3*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 + 3*3)
(2*3 + 2*3 + 3*3 + 3*3 + 3*3 + 3*3 + 3*3 + 3*3 + 3*3)

Crossrefs

Sequence in context: A067406 A046281 A180833 * A361889 A364369 A285926

Adjacent sequences: A180818 A180819 A180820 * A180822 A180823 A180824

Keyword

nonn

Author

R. H. Hardin Sep 20 2010

Status

approved