A180799 Number of distinct solutions of sum{i=1..7}(x(2i-1)*x(2i)) = 0 (mod n), with x() in 0..n-1.

1, 20, 270, 3000, 23282, 151473, 768541, 3422978, 12879078, 44111410, 133919379, 381516366, 988173838, 2446846672, 5633359713, 12527643860, 26226659375, 53655084387, 104124710377, 198817175068, 363133886202, 654527617329

Offset: 1

Author

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

Keywords

• nonn

Comments

Column 7 of A180803

Examples

			Solutions for sum of products of 7 0..1 pairs = 0 (mod 2) are
(0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*0)
(0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*1)
(0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 0*1 + 0*1)
(0*0 + 0*0 + 0*0 + 0*0 + 0*1 + 0*1 + 0*1)
(0*0 + 0*0 + 0*0 + 0*0 + 0*0 + 1*1 + 1*1)
(0*0 + 0*0 + 0*0 + 0*0 + 0*1 + 1*1 + 1*1)
(0*0 + 0*0 + 0*0 + 0*1 + 0*1 + 0*1 + 0*1)
(0*0 + 0*0 + 0*0 + 0*1 + 0*1 + 1*1 + 1*1)
(0*0 + 0*0 + 0*0 + 1*1 + 1*1 + 1*1 + 1*1)
(0*0 + 0*0 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1)
(0*0 + 0*0 + 0*1 + 0*1 + 0*1 + 1*1 + 1*1)
(0*0 + 0*0 + 0*1 + 1*1 + 1*1 + 1*1 + 1*1)
(0*0 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1)
(0*0 + 0*1 + 0*1 + 0*1 + 0*1 + 1*1 + 1*1)
(0*0 + 0*1 + 0*1 + 1*1 + 1*1 + 1*1 + 1*1)
(0*0 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1)
(0*1 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1 + 0*1)
(0*1 + 0*1 + 0*1 + 0*1 + 0*1 + 1*1 + 1*1)
(0*1 + 0*1 + 0*1 + 1*1 + 1*1 + 1*1 + 1*1)
(0*1 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1 + 1*1)
		

Links

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