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A232377
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Number of 2Xn 0..3 arrays with every 0 next to a 1, every 1 next to a 2 and every 2 next to a 3 horizontally, diagonally or antidiagonally, and no adjacent values equal
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1
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1, 14, 74, 296, 1130, 4682, 19448, 79592, 326810, 1343042, 5516132, 22658744, 93073958, 382310690, 1570402928, 6450645104, 26496901994, 108839752922, 447074397188, 1836420218672, 7543351642070, 30985365821066, 127276699845344
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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) +a(n-2) +13*a(n-3) +26*a(n-5) -4*a(n-6) +24*a(n-7) +16*a(n-8) for n>9.
Empirical: g.f.: x + 2*x*(-7 -16*x -30*x^2 +7*x^3 -17*x^4 -30*x^5 -4*x^6 +8*x^7) ) / ( (2*x^2+1)*(8*x^6 +12*x^5 -6*x^4 +7*x^3 +3*x^2 +3*x-1) ). - R. J. Mathar, Nov 27 2013
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EXAMPLE
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Some solutions for n=7
..3..0..1..2..1..0..3....0..3..2..3..0..3..0....2..1..2..3..0..3..2
..3..2..3..0..1..0..3....2..1..0..3..2..1..0....2..3..2..3..0..1..2
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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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