A317856 - OEIS

%I #4 Aug 09 2018 09:42:20

%S 0,3,4,56,350,3315,33238,517734,8875636,219127394,6925306920

%N Number of nXn 0..1 arrays with every element unequal to 1, 2 or 4 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.

%C Diagonal of A317863.

%e Some solutions for n=5

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

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

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

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

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

%Y Cf. A317863.

%K nonn

%O 1,2

%A _R. H. Hardin_, Aug 09 2018