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A180806 Number of distinct solutions of sum{i=1..4}(x(2i-1)*x(2i)) = 1 (mod n), with x() in 0..n-1 1
0, 6, 42, 166, 612, 1649, 4501, 9772, 21631, 39911, 78602, 131634, 234593, 361145, 603810, 883492, 1396448, 1928226, 2949092, 3948312, 5771436, 7496953, 10742472, 13520820, 18931459, 23338564, 31813882, 38799595, 52158316, 61609006, 82337294 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 4 of A180813

LINKS

R. H. Hardin, Table of n, a(n) for n=1..376

EXAMPLE

Solutions for sum of products of 4 0..1 pairs = 1 (mod 2) are

(0*0 + 0*0 + 0*0 + 1*1) (0*0 + 0*0 + 0*1 + 1*1) (0*0 + 0*1 + 0*1 + 1*1)

(0*0 + 1*1 + 1*1 + 1*1) (0*1 + 0*1 + 0*1 + 1*1) (0*1 + 1*1 + 1*1 + 1*1)

CROSSREFS

Sequence in context: A176780 A169938 A082986 * A253946 A062136 A047663

Adjacent sequences:  A180803 A180804 A180805 * A180807 A180808 A180809

KEYWORD

nonn

AUTHOR

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

STATUS

approved

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Last modified July 9 16:50 EDT 2020. Contains 335545 sequences. (Running on oeis4.)