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%I #8 Jan 24 2023 15:29:08
%S 0,4,72,3364,1700580,3743237124,44312000955508,2752746090434507556,
%T 840982281825673724760300,1273642755637661083775996170564
%N Number of n X n 0..2 arrays with every element neighboring horizontally or vertically both a 0 and a 1.
%C Diagonal of A203542.
%e Some solutions for n=5
%e ..0..1..2..0..1....1..1..0..0..0....2..1..0..0..2....0..0..1..0..1
%e ..0..1..2..0..1....0..2..2..1..1....0..1..2..1..1....1..1..1..0..1
%e ..2..1..2..0..2....0..2..1..0..1....0..1..1..2..0....1..0..1..0..0
%e ..1..0..0..1..0....1..1..1..0..0....1..2..0..2..0....0..0..1..0..1
%e ..1..0..1..1..0....1..0..0..1..1....1..0..0..1..1....2..1..1..0..1
%Y Cf. A203542.
%K nonn
%O 1,2
%A _R. H. Hardin_, Jan 02 2012
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