A215790 - OEIS

A215790

Number of permutations of 0..floor((4*n-1)/2) on even squares of an 4*n array such that each row, column, diagonal and (downwards) antidiagonal of even squares is increasing

1, 1, 1, 2, 10, 29, 262, 932, 11694, 46988, 727846, 3166688, 56797272, 261286670, 5219906670, 25024705056

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OFFSET

1,4

COMMENTS

Row 4 of A215788

LINKS

Table of n, a(n) for n=1..16.

EXAMPLE

Some solutions for n=5

..0..x..1..x..2....0..x..1..x..2....0..x..1..x..4....0..x..1..x..4

..x..3..x..4..x....x..3..x..5..x....x..2..x..5..x....x..2..x..5..x

..5..x..6..x..8....4..x..6..x..7....3..x..6..x..8....3..x..6..x..7

..x..7..x..9..x....x..8..x..9..x....x..7..x..9..x....x..8..x..9..x

CROSSREFS

Sequence in context: A047112 A190186 A032250 * A133485 A215954 A098425

Adjacent sequences: A215787 A215788 A215789 * A215791 A215792 A215793

KEYWORD

nonn

AUTHOR

R. H. Hardin Aug 23 2012

STATUS

approved