A303889 - OEIS

%I #6 Sep 16 2020 19:08:49

%S 0,7,54,1659,29479,1541443,71307109,5846922441,668263785713,

%T 103693982275562

%N Number of n X n 0..1 arrays with every element unequal to 1, 2, 3 or 4 king-move adjacent elements, with upper left element zero.

%C Diagonal of A303896.

%e Some solutions for n=5

%e ..0..0..0..1..1. .0..1..1..1..0. .0..0..1..1..1. .0..1..1..0..1

%e ..1..0..0..1..0. .0..0..1..1..1. .1..1..1..1..0. .0..1..1..1..0

%e ..1..0..1..1..0. .0..0..0..0..0. .0..1..0..0..0. .1..1..1..0..0

%e ..0..0..1..1..1. .1..0..0..0..0. .1..0..0..0..1. .0..1..0..0..0

%e ..0..1..0..0..1. .0..1..0..1..1. .0..0..1..1..1. .1..0..0..0..1

%Y Cf. A303896.

%K nonn

%O 1,2

%A _R. H. Hardin_, May 02 2018