A180787 Number of distinct solutions of sum{i=1..5}(x(2i-1)*x(2i)) = 1 (mod n), with x() only in 1..n-1.

0, 1, 5, 64, 400, 1914, 7589, 24902, 73134, 188315, 455127, 996083, 2098908, 4080930, 7790731, 13869018, 24527424, 40768032, 67955336, 106952861, 169909977, 255608028, 390623704, 566247614, 837326375, 1175991196, 1690928973

Offset: 1

Author

R. H. Hardin Sep 20 2010

Keywords

• nonn

Comments

Column 5 of A180793

Examples

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

Links

• R. H. Hardin, Table of n, a(n) for n=1..250