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A233897
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Number of (n+1) X (1+1) 0..6 arrays with every 2 X 2 subblock having the sum of the squares of all six edge and diagonal differences equal to 35.
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1
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144, 656, 2688, 12288, 51200, 233984, 987136, 4503552, 19185664, 87351296, 375062528, 1704296448, 7364935680, 33408548864, 145134452736, 657383227392, 2868195098624, 12975463202816, 56813072416768, 256757263761408
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OFFSET
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1,1
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LINKS
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FORMULA
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Empirical: a(n) = 44*a(n-2) - 608*a(n-4) + 2560*a(n-6).
Empirical g.f.: 16*x*(9 + 41*x - 228*x^2 - 1036*x^3 + 1280*x^4 + 5760*x^5) / ((1 - 4*x)*(1 + 4*x)*(1 - 8*x^2)*(1 - 20*x^2)). - Colin Barker, Oct 12 2018
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EXAMPLE
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Some solutions for n=5:
..4..1....3..4....1..3....2..1....5..4....1..4....3..1....2..3....1..5....1..3
..0..2....5..1....2..5....3..5....2..6....3..5....5..4....0..4....4..3....5..4
..1..4....4..3....3..1....2..1....4..5....1..2....2..6....1..2....5..1....2..6
..5..3....0..2....4..5....5..3....1..3....3..5....4..3....3..5....3..2....4..3
..1..2....4..3....2..6....2..1....5..4....1..4....2..0....4..1....4..6....6..2
..5..3....0..2....5..4....4..0....2..6....0..2....1..4....5..3....5..2....4..3
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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