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%I #6 Jun 26 2020 13:26:18
%S 0,3,53,2227,240196,67378450,48707694395,90693182026546,
%T 435112536711313866,5381527099060030118335,171582103150798864303410622
%N Number of n X n 0..1 arrays with every element equal to 1, 2 or 3 horizontally, vertically or antidiagonally adjacent elements, with upper left element zero.
%C Diagonal of A300427.
%e Some solutions for n=5
%e ..0..0..0..0..1. .0..0..0..0..0. .0..0..0..1..1. .0..0..0..1..1
%e ..0..1..0..1..1. .1..0..1..0..0. .0..1..0..1..0. .1..1..0..0..0
%e ..0..1..0..1..0. .1..0..1..1..0. .0..1..0..1..0. .0..1..1..0..1
%e ..0..1..0..0..0. .0..0..1..0..0. .1..1..0..0..1. .0..0..1..0..1
%e ..1..1..1..1..0. .1..1..0..1..1. .0..0..1..1..1. .0..0..1..1..1
%Y Cf. A300427.
%K nonn
%O 1,2
%A _R. H. Hardin_, Mar 05 2018