cp's OEIS Frontend

A222899 Number of n X n 0..3 arrays with no more than floor(n X n/2) elements unequal to at least one horizontal or antidiagonal neighbor, with new values introduced in row major 0..3 order.

%I A222899 #7 Apr 17 2022 17:49:59
%S A222899 1,4,45,7794,2117424,10615237672,51666240687220,4291633334520814783,
%T A222899 347033965049827951084160
%N A222899 Number of n X n 0..3 arrays with no more than floor(n X n/2) elements unequal to at least one horizontal or antidiagonal neighbor, with new values introduced in row major 0..3 order.
%C A222899 Diagonal of A222906.
%e A222899 Some solutions for n=3
%e A222899 ..0..0..1....0..1..2....0..0..0....0..0..1....0..1..2....0..0..1....0..0..1
%e A222899 ..2..2..2....1..1..1....0..0..1....2..3..3....2..2..2....0..1..1....0..0..0
%e A222899 ..2..2..2....1..1..1....2..0..0....3..3..3....2..2..2....1..1..1....0..0..0
%Y A222899 Cf. A222906.
%K A222899 nonn
%O A222899 1,2
%A A222899 _R. H. Hardin_, Mar 09 2013