%I #4 Nov 03 2012 13:43:04
%S 1,191,3567,56629,898763,14313773,228191491,3638365943,58007785937,
%T 924827168901,14744666323421,235076662350533,3747866807725781,
%U 59752871465350263,952650082055322631,15188260508053833233
%N Hilltop maps: number of 4Xn binary arrays indicating the locations of corresponding elements not exceeded by any horizontal or antidiagonal neighbor in a random 0..2 4Xn array
%C Row 4 of A218592
%H R. H. Hardin, <a href="/A218595/b218595.txt">Table of n, a(n) for n = 1..162</a>
%e Some solutions for n=3
%e ..0..0..1....1..0..0....1..1..0....0..1..1....0..0..1....0..1..1....1..0..0
%e ..0..0..0....0..0..1....1..0..0....1..1..1....1..1..0....0..1..1....1..0..1
%e ..1..0..1....1..0..0....1..0..1....1..1..0....1..1..0....1..1..0....0..0..1
%e ..1..0..0....0..1..1....1..1..1....0..0..1....1..1..1....1..1..0....1..1..0
%K nonn
%O 1,2
%A _R. H. Hardin_ Nov 03 2012