A215868 - OEIS

%I #4 Aug 25 2012 05:47:12

%S 1,14,110,3001,26451,767560,6812794,198409297,1761748159,51317680568,

%T 455678075546,13273519382093,117863060852067,3433253982499552,

%U 30485799411892266,888026282079787049,7885286478349158743

%N 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

%C Column 8 of A215870

%H R. H. Hardin, <a href="/A215868/b215868.txt">Table of n, a(n) for n = 1..210</a>

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

%e Some solutions for n=4

%e ..x..0..x..2..x..4..x..6....x..0..x..1..x..2..x..7....x..0..x..1..x..3..x..5

%e ..1..x..3..x..7..x..9..x....3..x..4..x..5..x..8..x....2..x..4..x..8..x..9..x

%e ..x..5..x..8..x.10..x.13....x..6..x.10..x.11..x.12....x..6..x.10..x.12..x.14

%e .11..x.12..x.14..x.15..x....9..x.13..x.14..x.15..x....7..x.11..x.13..x.15..x

%K nonn

%O 1,2

%A _R. H. Hardin_ Aug 25 2012