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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.

%I A215790 #7 Jul 22 2025 23:24:53
%S A215790 1,1,1,2,10,29,262,932,11694,46988,727846,3166688,56797272,261286670,
%T A215790 5219906670,25024705056
%N 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.
%C A215790 Row 4 of A215788
%e A215790 Some solutions for n=5
%e A215790 ..0..x..1..x..2....0..x..1..x..2....0..x..1..x..4....0..x..1..x..4
%e A215790 ..x..3..x..4..x....x..3..x..5..x....x..2..x..5..x....x..2..x..5..x
%e A215790 ..5..x..6..x..8....4..x..6..x..7....3..x..6..x..8....3..x..6..x..7
%e A215790 ..x..7..x..9..x....x..8..x..9..x....x..7..x..9..x....x..8..x..9..x
%K A215790 nonn
%O A215790 1,4
%A A215790 _R. H. Hardin_ Aug 23 2012