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A269829
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T(n,k)=Number of nXk 0..4 arrays with some element plus some horizontally, diagonally, antidiagonally or vertically adjacent neighbor totalling four exactly once.
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9
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0, 5, 5, 40, 216, 40, 240, 3096, 3096, 240, 1280, 39784, 103296, 39784, 1280, 6400, 462680, 3200604, 3200604, 462680, 6400, 30720, 5145736, 90748696, 240637408, 90748696, 5145736, 30720, 143360, 55265336, 2472983556, 16644595392
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OFFSET
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1,2
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COMMENTS
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Table starts
......0..........5.............40................240...................1280
......5........216...........3096..............39784.................462680
.....40.......3096.........103296............3200604...............90748696
....240......39784........3200604..........240637408............16644595392
...1280.....462680.......90748696........16644595392..........2840332868960
...6400....5145736.....2472983556......1109236460528........467693538063508
..30720...55265336....65284613232.....71730749075588......74936429415811576
.143360..580002280..1686961414812...4544255355000752...11771832152564634464
.655360.5978552216.42866673833128.283289815771686692.1821445245786662249776
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LINKS
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FORMULA
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Empirical for column k:
k=1: a(n) = 8*a(n-1) -16*a(n-2)
k=2: [order 6] for n>7
k=3: [order 18] for n>19
k=4: [order 48] for n>49
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EXAMPLE
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Some solutions for n=3 k=4
..0..0..3..3. .0..0..2..3. .0..0..2..3. .0..0..0..2. .0..1..4..1
..1..0..2..3. .0..1..3..3. .0..0..2..3. .1..0..1..0. .0..0..1..1
..1..1..3..3. .1..2..4..2. .3..3..3..0. .4..2..1..2. .0..1..2..1
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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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