A215868 Number of permutations of 0..floor((n*8-2)/2) on odd squares of an nX8 array such that each row, column, diagonal and (downwards) antidiagonal of odd squares is increasing.

1, 14, 110, 3001, 26451, 767560, 6812794, 198409297, 1761748159, 51317680568, 455678075546, 13273519382093, 117863060852067, 3433253982499552, 30485799411892266, 888026282079787049, 7885286478349158743

Offset: 1

Author

R. H. Hardin Aug 25 2012

Keywords

• nonn

Comments

Column 8 of A215870

Examples

			Some solutions for n=4
..x..0..x..2..x..4..x..6....x..0..x..1..x..2..x..7....x..0..x..1..x..3..x..5
..1..x..3..x..7..x..9..x....3..x..4..x..5..x..8..x....2..x..4..x..8..x..9..x
..x..5..x..8..x.10..x.13....x..6..x.10..x.11..x.12....x..6..x.10..x.12..x.14
.11..x.12..x.14..x.15..x....9..x.13..x.14..x.15..x....7..x.11..x.13..x.15..x
		

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)