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A180817 Number of distinct solutions of sum{i=1..5}(x(2i-1)*x(2i)) = 0 (mod n), with x() only in 2..n-2 1
0, 0, 0, 1, 7, 57, 286, 1701, 5969, 22212, 59824, 173319, 385060, 920819, 1831674, 3839358, 6872225, 13243078, 21945628, 39182616, 61892080, 103355368, 155139308, 251041955, 359562489, 554717344, 780642911, 1160794113, 1574984248 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,5

COMMENTS

Column 5 of A180823

LINKS

R. H. Hardin, Table of n, a(n) for n=1..251

EXAMPLE

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

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

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

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

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

CROSSREFS

Sequence in context: A304691 A218428 A274721 * A201438 A202510 A042187

Adjacent sequences:  A180814 A180815 A180816 * A180818 A180819 A180820

KEYWORD

nonn

AUTHOR

R. H. Hardin Sep 20 2010

STATUS

approved

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Last modified October 20 19:49 EDT 2021. Contains 348118 sequences. (Running on oeis4.)