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A265982
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Number of 2Xn integer arrays with each element equal to the number of horizontal, diagonal and antidiagonal neighbors less than itself.
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1
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1, 23, 117, 583, 5554, 52555, 405165, 3187023, 27556293, 236031924, 1954705747, 16303686375, 137792545601, 1160356891015, 9726964384242, 81685622645847, 687078560321849, 5774620905203231, 48507868973737037, 407612988439220460
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OFFSET
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1,2
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COMMENTS
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LINKS
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FORMULA
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Empirical: a(n) = 3*a(n-1) +7*a(n-2) +245*a(n-3) +843*a(n-4) +682*a(n-5) -8270*a(n-6) -75724*a(n-7) -128332*a(n-8) -57680*a(n-9) +40248*a(n-10) +1110976*a(n-11) +4466432*a(n-12) +43442944*a(n-13) +52444480*a(n-14) -196580480*a(n-15) -356820480*a(n-16) -145435136*a(n-17) +616442880*a(n-18) +696227840*a(n-19) -1809612800*a(n-20) +192880640*a(n-21) +1489469440*a(n-22) -2379874304*a(n-23) +991100928*a(n-24) -16384000*a(n-25) -25952256*a(n-26)
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EXAMPLE
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Some solutions for n=4
..0..3..0..0....0..3..4..1....1..0..0..0....1..0..0..1....1..0..3..0
..0..0..3..1....0..0..0..0....0..4..3..1....1..4..1..1....1..4..3..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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