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%I #7 Jan 27 2024 17:47:13
%S 9672,109655775,16256855591536,31112427702110512128,
%T 769885056390910177755092784,246208690739288821726563895377926727
%N Number of (n+2) X (n+2) 0..3 arrays with no 3 X 3 subblock having three equal diagonal elements or three equal antidiagonal elements, and new values 0..3 introduced in row major order.
%C Diagonal of A204351.
%e Some solutions for n=3
%e ..0..1..0..2..1....0..0..0..0..0....0..1..0..2..0....0..1..1..0..0
%e ..0..3..3..3..3....1..2..3..2..3....3..3..0..1..3....0..2..0..0..2
%e ..3..2..1..3..1....1..1..1..3..3....2..1..1..2..1....1..1..3..1..0
%e ..3..0..0..1..0....3..1..0..1..1....1..0..2..0..3....0..1..0..2..3
%e ..2..0..2..1..2....3..2..3..0..2....0..0..2..1..1....2..1..2..0..3
%Y Cf. A204351.
%K nonn
%O 1,1
%A _R. H. Hardin_, Jan 14 2012