%I #6 Apr 21 2020 12:38:31
%S 1,6,68,1632,84948,8960464,1980677448,905233056800,860544738080372,
%T 1705630286322728068
%N Number of n X n 0..2 arrays with no element equal to any value at offset (-1,-2), (-2,-1) or (-1,0) and new values introduced in order 0..2.
%C Diagonal of A274728.
%e Some solutions for n=4
%e ..0..0..1..0. .0..1..0..1. .0..1..1..1. .0..1..0..1. .0..1..2..0
%e ..2..1..2..2. .1..0..1..2. .1..0..2..0. .2..0..2..2. .1..0..1..2
%e ..1..2..1..0. .0..2..0..1. .2..1..0..2. .1..1..0..1. .2..1..0..1
%e ..0..0..0..1. .2..0..2..0. .0..0..1..0. .0..0..2..0. .1..0..1..2
%Y Cf. A274728.
%K nonn
%O 1,2
%A _R. H. Hardin_, Jul 03 2016