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A239845
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Number of nX3 0..3 arrays with no element equal to one plus the sum of elements to its left or one plus the sum of elements above it or two plus the sum of the elements diagonally to its northwest, modulo 4
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1
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4, 17, 68, 244, 777, 2221, 5853, 14488, 34057, 76495, 164823, 341898, 685019, 1329596, 2506729, 4601633, 8242778, 14435568, 24759659, 41655972, 68838529, 111877953, 179018454, 282309115, 439154169, 674416741, 1023247403, 1534854222
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OFFSET
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1,1
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COMMENTS
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LINKS
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FORMULA
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Empirical: a(n) = (1/6227020800)*n^13 - (1/119750400)*n^12 + (221/479001600)*n^11 - (103/10886400)*n^10 + (649/4838400)*n^9 + (3569/3628800)*n^8 - (2313347/43545600)*n^7 + (10192331/10886400)*n^6 - (87698557/10886400)*n^5 + (82688371/2721600)*n^4 + (101725069/1247400)*n^3 - (505121941/415800)*n^2 + (698568509/180180)*n - 2851 for n>9
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EXAMPLE
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Some solutions for n=4
..0..0..3....0..3..3....0..3..3....0..3..3....0..3..3....0..0..3....0..3..3
..0..3..3....0..3..3....0..3..3....3..1..3....0..3..2....0..0..3....3..1..2
..3..1..2....3..1..0....0..0..0....3..3..0....0..0..3....0..3..1....3..2..0
..3..2..0....3..2..0....3..1..0....0..2..1....0..0..3....3..3..2....0..0..0
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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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