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A252718
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Number of (n+2) X (7+2) 0..3 arrays with every consecutive three elements in every row and diagonal having exactly two distinct values, and in every column and antidiagonal not having exactly two distinct values, and new values 0 upwards introduced in row major order.
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1
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237, 107, 114, 153, 211, 270, 373, 522, 672, 938, 1322, 1704, 2388, 3379, 4354, 6113, 8673, 11166, 15693, 22312, 28696, 40358, 57486, 73856, 103928, 148285, 190314, 267933, 382891, 490926, 691453, 989592, 1267608, 1786118, 2559836, 3276048
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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) = 6*a(n-3) - 11*a(n-6) + 5*a(n-9) + 2*a(n-12) - a(n-15) for n>17.
Empirical g.f.: x*(237 + 107*x + 114*x^2 - 1269*x^3 - 431*x^4 - 414*x^5 + 2062*x^6 + 433*x^7 + 306*x^8 - 802*x^9 - 24*x^10 + 72*x^11 - 376*x^12 - 80*x^13 - 56*x^14 + 169*x^15 + 16*x^16) / ((1 - x)*(1 + x + x^2)*(1 - 3*x^3 + x^6)*(1 - 2*x^3 - x^6)). - Colin Barker, Dec 05 2018
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EXAMPLE
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Some solutions for n=4:
..0..0..1..0..0..2..0..0..2....0..1..0..0..1..0..0..1..0
..2..0..0..1..0..0..2..0..0....1..1..2..1..1..3..1..1..3
..3..0..3..3..0..3..3..0..3....3..1..1..2..1..1..3..1..1
..0..0..2..0..0..1..0..0..2....0..1..0..0..1..0..0..1..0
..1..0..0..2..0..0..1..0..0....1..1..3..1..1..2..1..1..3
..3..0..3..3..0..3..3..0..3....2..1..1..3..1..1..2..1..1
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CROSSREFS
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Column 7 of A252719.
Sequence in context: A233200 A233221 A265372 * A036270 A217030 A048454
Adjacent sequences: A252715 A252716 A252717 * A252719 A252720 A252721
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KEYWORD
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nonn
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AUTHOR
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R. H. Hardin, Dec 20 2014
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STATUS
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approved
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