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Number of 2Xn 0..2+n-2 arrays with upper left zero and lower right 2+n-2 and each element differing from its horizontal and antidiagonal neighbors by one or two.

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`%I #4 Dec 09 2015 10:48:47
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`%S 1,3,26,139,765,6221,46898,292690,1722770,10915890,73213113,480069015,
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`%T 3032127834,19084607287,122424984026,792495253960,5097255978957,
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`%U 32562226190102,208268070296589,1338186393004984,8611472163134863
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`%N Number of 2Xn 0..2+n-2 arrays with upper left zero and lower right 2+n-2 and each element differing from its horizontal and antidiagonal neighbors by one or two.
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`%C Row 2 of A265466.
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`%H R. H. Hardin, <a href="/A265467/b265467.txt">Table of n, a(n) for n = 1..210</a>
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`%e Some solutions for n=4
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`%e ..0..1..0..1....0..1..3..1....0..2..1..2....0..1..2..0....0..2..1..3
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`%e ..3..1..2..4....2..4..3..4....0..2..3..4....2..4..2..4....1..3..2..4
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`%Y Cf. A265466.
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`%K nonn
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`%O 1,2
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`%A _R. H. Hardin_, Dec 09 2015
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