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A068925
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Number of ways to tile a 6 X n room with 1x2 Tatami mats. At most 3 Tatami mats may meet at a point.
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2
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1, 9, 6, 3, 2, 2, 2, 1, 1, 2, 3, 4, 3, 3, 3, 4, 6, 6, 7, 6, 7, 9, 10, 13, 12, 14, 15, 17, 22, 22, 27, 27, 31, 37, 39, 49, 49, 58, 64, 70, 86, 88, 107, 113, 128, 150, 158, 193, 201, 235, 263, 286, 343, 359, 428, 464, 521, 606, 645, 771, 823, 949, 1070, 1166, 1377, 1468
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OFFSET
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1,2
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COMMENTS
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For n >= 12, a(n) = a(n-5) + a(n-7).
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LINKS
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FORMULA
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G.f.: x*(1-2*x^10-6*x^9-11*x^8-6*x^7-7*x^6+x^5+2*x^4+3*x^3+6*x^2+9*x)/(1-x^7-x^5) [From Maksym Voznyy (voznyy(AT)mail.ru), Aug 11 2009]
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CROSSREFS
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KEYWORD
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easy,nonn
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AUTHOR
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EXTENSIONS
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G.f. proposed by Maksym Voznyy checked and corrected by R. J. Mathar, Sep 16 2009.
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STATUS
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approved
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