A180794 Number of distinct solutions of sum{i=1..2}(x(2i-1)*x(2i)) = 0 (mod n), with x() in 0..n-1.

1, 4, 8, 20, 28, 56, 64, 122, 150, 218, 216, 424, 346, 544, 667, 863, 733, 1305, 1000, 1752, 1715, 1944, 1728, 3258, 2535, 3142, 3495, 4520, 3382, 6254, 4096, 6486, 6243, 6812, 7315, 10959, 6868, 9400, 10121, 13922, 9271, 16388, 10648, 16520, 17805

Offset: 1

Author

R. H. Hardin, suggested by Max Alekseyev in the Sequence Fans Mailing List, Sep 20 2010

Keywords

• nonn

Comments

Column 2 of A180803

Examples

			Solutions for sum of products of 2 0..4 pairs = 0 (mod 5) are
(0*0 + 0*0) (0*0 + 0*1) (0*0 + 0*2) (0*0 + 0*3) (0*0 + 0*4) (0*1 + 0*1)
(0*1 + 0*2) (0*1 + 0*3) (0*1 + 0*4) (0*2 + 0*2) (0*2 + 0*3) (0*2 + 0*4)
(0*3 + 0*3) (0*3 + 0*4) (0*4 + 0*4) (1*1 + 1*4) (1*1 + 2*2) (1*1 + 3*3)
(1*2 + 1*3) (1*2 + 2*4) (1*3 + 3*4) (1*4 + 2*3) (1*4 + 4*4) (2*2 + 2*3)
(2*2 + 4*4) (2*3 + 3*3) (2*4 + 3*4) (3*3 + 4*4)
		

Links

• R. H. Hardin, Table of n, a(n) for n=1..999