%I #5 Mar 31 2012 12:37:23
%S 2,12,152,3024,84124,3057664,139056380,7675358704,502604958608,
%T 38359095933912,3363791582993716,334974400169588800,
%U 37509570331200251508,4683620100177290725336,647429265450114057846496
%N Number of 2Xn nonnegative integer arrays with new values 0 upwards introduced in row major order and no element equal to more than one of its immediate leftward or upward or right-upward antidiagonal neighbors
%C Row 2 of A208581
%H R. H. Hardin, <a href="/A208582/b208582.txt">Table of n, a(n) for n = 1..27</a>
%e Some solutions for n=4
%e ..0..0..0..0....0..0..1..0....0..0..1..1....0..0..0..1....0..0..0..0
%e ..1..1..2..0....1..2..0..1....1..2..0..0....1..1..0..2....1..1..1..0
%K nonn
%O 1,1
%A _R. H. Hardin_ Feb 29 2012