A180790 Number of distinct solutions of sum{i=1..8}(x(2i-1)*x(2i)) = 1 (mod n), with x() only in 1..n-1.

0, 0, 12, 318, 4868, 53133, 444019, 2935676, 16112283, 75118525, 307372602, 1118328968, 3701885454, 11222027568, 31699803817, 83633494240, 209004408969, 494557127475, 1121475446283, 2431614016920, 5096216430113, 10285962253471

Offset: 1

Author

R. H. Hardin Sep 20 2010

Keywords

• nonn

Comments

Column 8 of A180793

Examples

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

Links

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