%I #7 Apr 14 2020 21:32:10
%S 1,6,20,67,393,4133,86487,3590263,285034170,43174729552,
%T 12383193287684,6712873423988949,6871475875643572553,
%U 13272675681120501977922,48367944991570243925176462,332490278773637201581189154380
%N Number of n X n 0..1 arrays with every element unequal to 0, 1, 2 or 6 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
%C Diagonal of A318343.
%H R. H. Hardin, <a href="/A318337/b318337.txt">Table of n, a(n) for n = 1..17</a>
%e Some solutions for n=5
%e ..0..1..1..1..1. .0..0..0..0..0. .0..0..0..0..0. .0..1..1..1..1
%e ..0..1..1..1..1. .0..1..0..0..0. .0..0..0..0..0. .1..1..1..1..0
%e ..0..1..1..1..1. .0..0..0..0..0. .0..0..0..0..0. .1..1..1..0..0
%e ..0..1..1..1..1. .0..0..0..0..0. .0..0..1..0..0. .1..1..0..0..0
%e ..0..1..1..1..0. .1..1..1..1..1. .0..0..0..0..0. .1..0..0..0..0
%Y Cf. A318343.
%K nonn
%O 1,2
%A _R. H. Hardin_, Aug 24 2018