%I #4 Aug 06 2018 11:47:56
%S 1,6,16,43,109,266,639,1529,3674,8909,21853,54252,136213,345373,
%T 882828,2271143,5871373,15234214,39633091,103306417,269641062,
%U 704462713,1841692605,4816973880,12602801545
%N Number of nXn 0..1 arrays with every element unequal to 0, 1 or 2 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
%C Diagonal of A317764.
%e Some solutions for n=5
%e ..0..1..1..1..1. .0..1..1..1..1. .0..1..1..1..1. .0..0..0..0..0
%e ..1..1..1..1..1. .1..1..1..1..1. .1..1..1..1..1. .0..0..0..0..0
%e ..0..0..0..0..0. .1..1..1..1..1. .1..1..1..1..1. .0..0..0..0..0
%e ..0..0..0..0..1. .1..1..1..1..1. .1..1..1..1..0. .0..0..0..0..0
%e ..0..0..0..1..1. .0..0..0..0..0. .1..1..1..0..0. .0..0..0..0..1
%Y Cf. A317764.
%K nonn
%O 1,2
%A _R. H. Hardin_, Aug 06 2018
|