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A268470 Number of nX2 arrays containing 2 copies of 0..n-1 with column sums equal. 0
1, 4, 36, 648, 19800, 972000, 69060600, 6756825600, 866219961600, 140837901120000, 28269530815680000, 6865910948635200000 (list; graph; refs; listen; history; text; internal format)
OFFSET
1,2
COMMENTS
Column 2 of A268472.
LINKS
EXAMPLE
Some solutions for n=4
..3..1. .1..1. .2..1. .1..0. .0..0. .3..2. .0..3. .3..3. .2..2. .1..2
..1..3. .0..3. .1..3. .2..3. .2..3. .0..3. .1..0. .2..0. .3..3. .0..0
..0..0. .3..2. .3..2. .0..1. .1..2. .1..0. .3..1. .1..2. .1..1. .2..3
..2..2. .2..0. .0..0. .3..2. .3..1. .2..1. .2..2. .0..1. .0..0. .3..1
CROSSREFS
Cf. A268472.
Sequence in context: A002761 A002084 A135867 * A365650 A214347 A208732
KEYWORD
nonn
AUTHOR
R. H. Hardin, Feb 05 2016
STATUS
approved

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Last modified March 28 13:25 EDT 2024. Contains 371254 sequences. (Running on oeis4.)