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A235091
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Number of (n+1) X (1+1) 0..5 arrays with every 2 X 2 subblock having its diagonal sum differing from its antidiagonal sum by 4, with no adjacent elements equal (constant stress tilted 1 X 1 tilings).
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1
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80, 256, 808, 2580, 8184, 26164, 83224, 266572, 849688, 2726852, 8707160, 27993324, 89526552, 288291140, 923287256, 2977443116, 9547498136, 30828553348, 98964094552, 319913934828, 1027967064600, 3326345126596, 10697524464088
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OFFSET
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1,1
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LINKS
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R. H. Hardin, Table of n, a(n) for n = 1..210
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FORMULA
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Empirical: a(n) = 3*a(n-1) + 13*a(n-2) - 39*a(n-3) - 26*a(n-4) + 78*a(n-5).
Empirical g.f.: 4*x*(20 + 4*x - 250*x^2 - 13*x^3 + 501*x^4) / ((1 - 3*x)*(1 - 13*x^2 + 26*x^4)). - Colin Barker, Oct 17 2018
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EXAMPLE
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Some solutions for n=4:
..0..3....4..2....3..2....5..2....5..2....1..2....0..1....4..1....2..5....2..5
..1..0....2..4....5..0....3..4....3..4....4..1....5..2....3..4....4..3....5..4
..0..3....4..2....2..1....4..1....0..5....3..4....2..3....4..1....2..5....0..3
..1..0....2..4....5..0....1..2....2..3....0..5....0..5....1..2....4..3....2..1
..2..5....3..1....2..1....3..0....5..2....3..4....1..2....4..1....2..5....0..3
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CROSSREFS
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Column 1 of A235098.
Sequence in context: A203355 A203348 A235098 * A306434 A234890 A157912
Adjacent sequences: A235088 A235089 A235090 * A235092 A235093 A235094
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KEYWORD
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nonn
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AUTHOR
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R. H. Hardin, Jan 03 2014
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STATUS
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approved
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