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Number of nX3 0..n*3-1 arrays with upper left zero and lower right n*3-1 and each element differing from its horizontal and antidiagonal neighbors by a power of two.
1

%I #4 Dec 10 2015 07:51:06

%S 1,84,9327,1427680,308395359,99770416100,38840832559548,

%T 10692035281792418,4325881418160722213,1373485273994265714224,

%U 622008060358478772620983,286739797768833085519267516

%N Number of nX3 0..n*3-1 arrays with upper left zero and lower right n*3-1 and each element differing from its horizontal and antidiagonal neighbors by a power of two.

%C Column 3 of A265590.

%H R. H. Hardin, <a href="/A265586/b265586.txt">Table of n, a(n) for n = 1..210</a>

%e Some solutions for n=3

%e ..0..4..8....0..8..4....0..2..6....0..1..5....0..4..5....0..4..2....0..8..6

%e ..8..4..5....7..3..2....0..4..8....2..4..6....8..6..2....6..4..8....6..7..8

%e ..5..4..8....2..4..8....5..6..8....8..7..8....4..0..8....3..4..8....6..7..8

%Y Cf. A265590.

%K nonn

%O 1,2

%A _R. H. Hardin_, Dec 10 2015