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A225341 Number of nX5 -1,1 arrays such that the sum over i=1..n,j=1..5 of i*x(i,j) is zero, the sum of x(i,j) is zero, and rows are nondecreasing (number of ways to distribute 5-across galley oarsmen left-right at n fore-aft positions so that there are no turning moments on the ship) 1
0, 0, 0, 12, 0, 0, 0, 4508, 0, 0, 0, 2680534, 0, 0, 0, 1985837462, 0, 0, 0, 1663045511892, 0, 0, 0, 1506336601246000, 0, 0, 0, 1440828827246863370, 0, 0, 0, 1434551060282150636452, 0, 0, 0, 1472882578482323918604276, 0, 0, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

COMMENTS

Column 5 of A225345

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..123

EXAMPLE

Some solutions for n=4

.-1.-1.-1.-1..1...-1.-1.-1.-1.-1....1..1..1..1..1...-1.-1.-1..1..1

.-1..1..1..1..1....1..1..1..1..1...-1.-1.-1.-1.-1...-1..1..1..1..1

.-1..1..1..1..1....1..1..1..1..1...-1.-1.-1.-1.-1...-1.-1.-1.-1..1

.-1.-1.-1.-1..1...-1.-1.-1.-1.-1....1..1..1..1..1...-1.-1..1..1..1

CROSSREFS

Sequence in context: A280832 A104203 A242240 * A004012 A270256 A072837

Adjacent sequences:  A225338 A225339 A225340 * A225342 A225343 A225344

KEYWORD

nonn

AUTHOR

R. H. Hardin May 05 2013

STATUS

approved

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Last modified February 22 19:51 EST 2019. Contains 320403 sequences. (Running on oeis4.)