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Number of (n+1) X (1+1) 0..1 arrays with the sum of each 2X2 2 X 2 subblock two extreme terms minus its two median terms lexicographically nondecreasing rowwise and columnwise.
Column 1 of A235555.
Empirical: a(n) = 2*a(n-1) + 4*a(n-2) - 8*a(n-3) - 4*a(n-4) + 8*a(n-5).
Empirical g.f.: 2*x*(8 + 7*x - 18*x^2 - 4*x^3 + 18*x^4) / ((1 - 2*x)*(1 - 2*x^2)^2). - Colin Barker, Mar 19 2018
Some solutions for n=5:
Cf. A235555.
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R. H. Hardin, <a href="/A235549/b235549.txt">Table of n, a(n) for n = 1..210</a>
allocated for R. H. Hardin
Number of (n+1)X(1+1) 0..1 arrays with the sum of each 2X2 subblock two extreme terms minus its two median terms lexicographically nondecreasing rowwise and columnwise
16, 46, 120, 288, 660, 1456, 3136, 6624, 13808, 28480, 58304, 118656, 240448, 485632, 978432, 1967616, 3951360, 7926784, 15889408, 31832064, 63742976, 127602688, 255377408, 511008768, 1022390272, 2045329408, 4091461632, 8184102912
1,1
Column 1 of A235555
Empirical: a(n) = 2*a(n-1) +4*a(n-2) -8*a(n-3) -4*a(n-4) +8*a(n-5)
Some solutions for n=5
..0..1....0..0....1..0....1..1....1..0....1..1....0..0....1..1....0..1....0..0
..1..1....1..1....1..0....1..0....1..0....1..0....1..1....1..0....1..0....0..0
..0..1....0..0....0..1....1..0....0..1....1..1....0..0....1..1....1..0....0..0
..1..1....0..0....0..1....1..0....0..1....1..0....0..0....0..1....0..0....0..0
..0..0....0..0....0..0....1..0....0..1....1..1....1..1....0..1....1..0....0..0
..0..0....1..1....1..0....0..0....1..0....0..0....1..1....0..1....0..0....1..1
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nonn
R. H. Hardin, Jan 12 2014
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