A180774 - OEIS

A180774

Number of distinct solutions of sum{i=1..3}(x(2i-1)*x(2i)) = 0 (mod n), with x() only in 1..n-1

0, 0, 5, 14, 42, 119, 253, 526, 944, 1702, 2655, 4510, 6284, 9867, 13519, 19980, 25128, 37286, 44562, 63802, 76850, 102370, 118591, 168208, 183320, 241554, 279852, 359754, 387016, 528861, 543620, 712450, 780810, 953120, 1025355, 1360255

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OFFSET

1,3

COMMENTS

Column 3 of A180782

LINKS

R. H. Hardin, Table of n, a(n) for n=1..447

EXAMPLE

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

(1*1 + 1*1 + 1*2) (1*1 + 1*1 + 2*3) (1*1 + 1*2 + 3*3) (1*1 + 1*3 + 2*2)

(1*1 + 2*3 + 3*3) (1*2 + 1*2 + 2*2) (1*2 + 1*3 + 1*3) (1*2 + 2*2 + 2*3)

(1*2 + 3*3 + 3*3) (1*3 + 1*3 + 2*3) (1*3 + 2*2 + 3*3) (2*2 + 2*2 + 2*2)

(2*2 + 2*3 + 2*3) (2*3 + 3*3 + 3*3)

CROSSREFS

Sequence in context: A266941 A034549 A232492 * A210972 A197607 A296829

Adjacent sequences: A180771 A180772 A180773 * A180775 A180776 A180777

KEYWORD

nonn

AUTHOR

R. H. Hardin Sep 20 2010

STATUS

approved