%I #6 Jun 22 2022 10:51:02

%S 2700,178608,13305708,820317888,51048476748,3154520054700,

%T 194576103540300,11996844809605932,739805051154249408,

%U 45610762080137185200,2812209212644935163212,173386992056092099438572

%N Number of (n+3) X (3+3) 0..2 arrays x(i,j) with each element diagonally or antidiagonally next to at least one element with value (x(i,j)+1) mod 3, and upper left element zero.

%C Column 3 of A230757.

%H R. H. Hardin, <a href="/A230752/b230752.txt">Table of n, a(n) for n = 1..210</a>

%e Some solutions for n=1

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

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

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

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

%Y Cf. A230757.

%K nonn

%O 1,1

%A _R. H. Hardin_, Oct 29 2013