A269195 - OEIS

%I #6 Apr 20 2020 19:51:23

%S 4,180,25572,15289548,34838403756,320994710282892,

%T 12093315071771856492,1887658657444603460395332,

%U 1230222115345954315761363474780,3366670969596963372379333414861881876

%N Number of n X n 0..3 arrays with some element plus some horizontally, diagonally or antidiagonally adjacent neighbor totalling three no more than once.

%C Diagonal of A269201.

%e Some solutions for n=3

%e ..0..2..0. .0..1..0. .3..1..3. .0..0..1. .1..0..0. .3..1..2. .0..0..0

%e ..0..1..3. .1..1..1. .0..3..3. .0..0..1. .1..0..1. .3..2..0. .2..0..0

%e ..0..1..3. .3..1..3. .3..1..1. .0..1..0. .3..3..1. .2..2..0. .2..0..1

%Y Cf. A269201.

%K nonn

%O 1,1

%A _R. H. Hardin_, Feb 20 2016