

A068923


Number of ways to tile a 4 X n room with 1x2 Tatami mats. At most 3 Tatami mats may meet at a point.


3



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
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OFFSET

1,2


LINKS

Table of n, a(n) for n=1..55.
R. J. Mathar, Paving rectangular regions with rectangular tiles,...., arXiv:1311.6135 [math.CO], Table 3.
Index entries for linear recurrences with constant coefficients, signature (0,0,1,0,1).


FORMULA

For n >= 9, a(n) = a(n3) + a(n5).
G.f.: x*(x+1)*(2*x^6+x^5+x^4x^23*x1)/(1+x^5+x^3) [From Maksym Voznyy (voznyy(AT)mail.ru), Jul 28 2009]


CROSSREFS

Cf. A068929 for incongruent tilings, A068920 for more info. First column of A272473.
Sequence in context: A146899 A317726 A031351 * A222295 A103714 A260486
Adjacent sequences: A068920 A068921 A068922 * A068924 A068925 A068926


KEYWORD

easy,nonn


AUTHOR

Dean Hickerson, Mar 11 2002


EXTENSIONS

G.f. proposed by Maksym Voznyy checked and corrected by R. J. Mathar, Sep 16 2009.


STATUS

approved



