A180788 - OEIS

A180788

Number of distinct solutions of sum{i=1..6}(x(2i-1)*x(2i)) = 1 (mod n), with x() only in 1..n-1

0, 0, 9, 112, 1004, 6404, 32890, 137528, 499641, 1579113, 4551268, 11861187, 29034355, 65777365, 142805210, 291148080, 576393509, 1082580072, 1993354411, 3505999065, 6088877416, 10148269838, 16796812567, 26776385524, 42563703291

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,3

COMMENTS

Column 6 of A180793

LINKS

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

EXAMPLE

Solutions for sum of products of 6 1..2 pairs = 1 (mod 3) are

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

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

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

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

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

CROSSREFS

Sequence in context: A352384 A143167 A201532 * A348068 A241804 A156949

Adjacent sequences: A180785 A180786 A180787 * A180789 A180790 A180791

KEYWORD

nonn

AUTHOR

R. H. Hardin Sep 20 2010

STATUS

approved