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A221627
Number of 5Xn arrays with each row a permutation of 1..n having at least as many downsteps as the preceding row
1
1, 6, 1818, 1130256, 3451956516, 21241004664348, 332469512259607296, 9510929074212911717760, 521875340203828179569609700, 47602100904962622927705491352020, 7181861163349151796773697873026037828
OFFSET
1,2
COMMENTS
Row 5 of A221623
LINKS
EXAMPLE
Some solutions for n=3
..1..3..2....1..3..2....2..3..1....3..1..2....2..1..3....1..3..2....3..1..2
..1..3..2....1..3..2....1..3..2....2..3..1....2..1..3....3..1..2....2..1..3
..2..1..3....2..1..3....1..3..2....3..1..2....2..1..3....2..1..3....3..1..2
..2..1..3....1..3..2....2..3..1....2..1..3....3..2..1....1..3..2....2..3..1
..2..3..1....2..3..1....1..3..2....1..3..2....3..2..1....3..2..1....3..1..2
CROSSREFS
Sequence in context: A258900 A357760 A250393 * A160301 A209496 A372525
KEYWORD
nonn
AUTHOR
R. H. Hardin Jan 21 2013
STATUS
approved