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%I #6 Jun 18 2022 18:52:27
%S 81,2471,203517,55635639,48557573047,149399847864279,
%T 1491726036815254275,48504233592897621172359
%N Number of (n+1) X (n+1) 0..2 arrays with the upper median minus the lower median of every 2 X 2 subblock equal.
%C Diagonal of A236737.
%e Some solutions for n=2
%e ..0..0..0....1..2..0....1..0..2....1..2..1....0..1..1....0..0..0....2..2..1
%e ..1..0..2....0..1..1....0..1..2....0..2..1....2..2..2....2..1..1....1..0..2
%e ..2..1..1....1..1..0....2..0..2....2..1..2....0..1..1....1..2..2....0..1..0
%Y Cf. A236737.
%K nonn
%O 1,1
%A _R. H. Hardin_, Jan 30 2014