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A068923
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Number of ways to tile a 4 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, 4, 4, 2, 3, 3, 3, 5, 5, 6, 8, 8, 11, 13, 14, 19, 21, 25, 32, 35, 44, 53, 60, 76, 88, 104, 129, 148, 180, 217, 252, 309, 365, 432, 526, 617, 741, 891, 1049, 1267, 1508, 1790, 2158, 2557, 3057, 3666, 4347, 5215, 6223, 7404, 8881, 10570, 12619, 15104, 17974
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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FORMULA
| For n >= 9, a(n) = a(n-3) + a(n-5).
G.f.: x*(x+1)*(2*x^6+x^5+x^4-x^2-3*x-1)/(-1+x^5+x^3) [From Maksym Voznyy (voznyy(AT)mail.ru), Jul 28 2009]
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CROSSREFS
| Cf. A068929 for incongruent tilings, A068920 for more info.
Sequence in context: A099655 A146899 A031351 * A103714 A193514 A112108
Adjacent sequences: A068920 A068921 A068922 * A068924 A068925 A068926
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KEYWORD
| easy,nonn
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AUTHOR
| Dean Hickerson (dean.hickerson(AT)yahoo.com), Mar 11 2002
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EXTENSIONS
| G.f. proposed by Maksym Voznyy checked and corrected by R. J. Mathar, Sep 16 2009.
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