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A215786 Number of permutations of 0..floor((n*8-1)/2) on even squares of an nX8 array such that each row, column, diagonal and (downwards) antidiagonal of even squares is increasing 1
1, 5, 110, 932, 26451, 234217, 6812794, 60485308, 1761748159, 15643423061, 455678075546, 4046220880948, 117863060852067, 1046572601513969, 30485799411892266, 270700616010831020, 7885286478349158743 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

Column 8 of A215788

LINKS

R. H. Hardin, Table of n, a(n) for n = 1..210

FORMULA

Empirical: a(n) = 272*a(n-2) -3439*a(n-4) -3336*a(n-6) +140*a(n-8)

EXAMPLE

Some solutions for n=4

..0..x..1..x..3..x..7..x....0..x..1..x..2..x..3..x....0..x..1..x..2..x..5..x

..x..2..x..4..x..9..x.10....x..4..x..6..x..7..x..8....x..3..x..4..x..7..x.11

..5..x..6..x.11..x.12..x....5..x..9..x.10..x.12..x....6..x..8..x..9..x.13..x

..x..8..x.13..x.14..x.15....x.11..x.13..x.14..x.15....x.10..x.12..x.14..x.15

CROSSREFS

Sequence in context: A177680 A281762 A265082 * A053133 A203367 A322631

Adjacent sequences:  A215783 A215784 A215785 * A215787 A215788 A215789

KEYWORD

nonn

AUTHOR

R. H. Hardin Aug 23 2012

STATUS

approved

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Last modified August 10 13:30 EDT 2020. Contains 336381 sequences. (Running on oeis4.)