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%I #7 Apr 23 2021 11:32:16
%S 0,1,1,6,35,675,17727,1019259,90018848,14424049245,3763663443702,
%T 1688522843271598,1263001202178738616
%N Number of n X n symmetric 0..3 arrays with each element equal to at least two horizontal or vertical neighbors and with new values 0..3 introduced in lower triangular row major order.
%e Some solutions for 8 X 8 containing a 3
%e ..0..0..0..0..2..2..1..1....0..0..0..0..0..0..0..0....0..0..0..0..2..2..2..2
%e ..0..0..0..0..2..2..1..1....0..0..0..0..0..0..0..0....0..0..0..0..2..2..2..2
%e ..0..0..1..1..1..1..3..3....0..0..0..0..0..0..0..0....0..0..1..1..1..1..1..1
%e ..0..0..1..2..2..1..3..3....0..0..0..0..1..1..0..0....0..0..1..1..2..2..1..1
%e ..2..2..1..2..2..1..2..2....0..0..0..1..1..1..2..2....2..2..1..2..2..2..3..3
%e ..2..2..1..1..1..1..2..2....0..0..0..1..1..1..2..2....2..2..1..2..2..2..3..3
%e ..1..1..3..3..2..2..2..2....0..0..0..0..2..2..3..3....2..2..1..1..3..3..3..3
%e ..1..1..3..3..2..2..2..2....0..0..0..0..2..2..3..3....2..2..1..1..3..3..3..3
%K nonn
%O 1,4
%A _R. H. Hardin_ Jul 14 2011