A180785 - OEIS

A180785

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

0, 1, 3, 14, 46, 106, 254, 494, 939, 1528, 2668, 3958, 6334, 8641, 13239, 17240, 25227, 31128, 44660, 53786, 74111, 86712, 118779, 134632, 181755, 202431, 266175, 296323, 387533, 412008, 544121, 582432, 736568, 786710, 1006750, 1037604, 1336781

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OFFSET

1,3

COMMENTS

Column 3 of A180793

LINKS

R. H. Hardin, Table of n, a(n) for n=1..444

EXAMPLE

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

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

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

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

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

CROSSREFS

Sequence in context: A032225 A032150 A032055 * A123350 A027953 A264501

Adjacent sequences: A180782 A180783 A180784 * A180786 A180787 A180788

KEYWORD

nonn

AUTHOR

R. H. Hardin Sep 20 2010

STATUS

approved