A180776 Number of distinct solutions of sum{i=1..5}(x(2i-1)*x(2i)) = 0 (mod n), with x() only in 1..n-1.

0, 0, 7, 62, 402, 1960, 7587, 25470, 73146, 193036, 455161, 1022770, 2098782, 4196208, 7797217, 14286908, 24527232, 42125055, 67955391, 110571248, 170260213, 264585538, 390623343, 588725404, 837466268, 1220597598, 1696535256

Offset: 1

Author

R. H. Hardin Sep 20 2010

Keywords

• nonn

Comments

Column 5 of A180782

Examples

			Solutions for sum of products of 5 1..2 pairs = 0 (mod 3) are
(1*1 + 1*1 + 1*1 + 1*1 + 1*2) (1*1 + 1*1 + 1*1 + 1*2 + 2*2)
(1*1 + 1*1 + 1*2 + 2*2 + 2*2) (1*1 + 1*2 + 1*2 + 1*2 + 1*2)
(1*1 + 1*2 + 2*2 + 2*2 + 2*2) (1*2 + 1*2 + 1*2 + 1*2 + 2*2)
(1*2 + 2*2 + 2*2 + 2*2 + 2*2)
		

Links

• R. H. Hardin, Table of n, a(n) for n=1..249