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A240433
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T(n,k)=Number of nXk 0..3 arrays with no element equal to zero plus the sum of elements to its left or zero plus the sum of the elements above it or two plus the sum of the elements diagonally to its northwest, modulo 4
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6
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2, 2, 2, 4, 6, 4, 4, 24, 24, 4, 8, 58, 206, 58, 8, 8, 236, 970, 970, 236, 8, 16, 566, 8084, 9036, 8084, 566, 16, 16, 2322, 38406, 150350, 150350, 38406, 2322, 16, 32, 5578, 319164, 1404008, 5087802, 1404008, 319164, 5578, 32, 32, 22912, 1514122, 23414762
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OFFSET
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1,1
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COMMENTS
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Table starts
..2.....2........4...........4..............8...............8...............16
..2.....6.......24..........58............236.............566.............2322
..4....24......206.........970...........8084...........38406...........319164
..4....58......970........9036.........150350.........1404008.........23414762
..8...236.....8084......150350........5087802........94860720.......3184383016
..8...566....38406.....1404008.......94860720......3523795084.....237034323164
.16..2322...319164....23414762.....3184383016....237034323164...32020507274002
.16..5578..1514122...218412550....59125702284...8779074387924.2372829502697230
.32.22912.12567490..3639548326..1979684295626.589446737374098
.32.55054.59600672.33928317272.36705060609854
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LINKS
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FORMULA
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Empirical for column k:
k=1: a(n) = 2*a(n-2)
k=2: a(n) = 12*a(n-2) -24*a(n-4) +31*a(n-6) -16*a(n-8)
k=3: [order 48]
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EXAMPLE
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Some solutions for n=4 k=4
..3..1..1..3....1..3..3..1....1..3..3..1....1..3..3..1....1..3..3..1
..1..2..2..2....3..2..2..0....3..2..2..0....3..2..2..0....3..0..2..2
..1..2..1..3....1..0..0..0....3..0..0..0....3..2..0..2....3..0..2..0
..3..2..3..2....3..2..0..3....1..2..2..0....1..0..2..0....1..0..2..0
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CROSSREFS
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KEYWORD
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AUTHOR
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STATUS
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approved
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