%I #7 Dec 18 2015 18:18:04
%S 1,8,196,16084,4226368,3613193828,10001404535216,89755737081698964,
%T 2610569024927748701352,246105734855228896970291844,
%U 75198808251676193628977268566832,74474161314983311603786393034039933768
%N Number of n X n 0..1 arrays with new values 0..1 introduced in row major order and no element equal to more than two of its immediate leftward or upward or right-upward antidiagonal neighbors
%C Diagonal of A208709
%H R. H. Hardin, <a href="/A208703/b208703.txt">Table of n, a(n) for n = 1..20</a>
%e Some solutions for n=4
%e ..0..0..1..0....0..0..0..1....0..1..0..1....0..0..0..1....0..1..1..0
%e ..0..0..1..0....1..0..1..1....1..0..1..1....1..0..0..0....0..0..1..0
%e ..1..1..0..0....0..0..1..0....0..0..0..1....1..1..1..1....0..0..1..1
%e ..1..1..0..0....0..1..0..0....0..1..0..1....1..0..1..1....1..0..0..0
%K nonn
%O 1,2
%A _R. H. Hardin_ Mar 01 2012