|
Search: id:A068929
|
|
|
| A068929 |
|
Number of incongruent ways to tile a 4 X n room with 1x2 Tatami mats. At most 3 Tatami mats may meet at a point. |
|
+0
3
|
|
| 1, 3, 2, 1, 2, 2, 2, 3, 3, 4, 5, 5, 6, 8, 8, 11, 12, 14, 17, 20, 24, 29, 32, 41, 46, 56, 68, 78, 93, 114, 130, 161, 188, 223, 268, 318, 378, 456, 533, 646, 763, 911, 1092, 1296, 1542, 1855, 2190, 2634, 3133, 3732, 4463, 5323, 6339, 7596, 9022, 10802, 12876
(list; graph; listen)
|
|
|
OFFSET
|
1,2
|
|
|
FORMULA
|
For n >= 20, a(n) = a(n-3) + a(n-5) + a(n-6) - a(n-9) + a(n-10) - a(n-11) - a(n-13) - a(n-15).
G.f.: x*(1-x^18+x^17+x^16+x^15+x^13-x^12-2*x^11-2*x^8-4*x^7-3*x^6-x^5-x^4+2*x^2+3*x) / ((x^5+x^3-1) * (x^10+x^6-1)) [From Maksym Voznyy (voznyy(AT)mail.ru), Aug 11 2009]
|
|
CROSSREFS
|
Cf. A068923 for total number of tilings, A068926 for more info.
Sequence in context: A096248 A079109 A079099 this_sequence A060567 A036583 A047878
Adjacent sequences: A068926 A068927 A068928 this_sequence A068930 A068931 A068932
|
|
KEYWORD
|
easy,nonn
|
|
AUTHOR
|
Dean Hickerson (dean.hickerson(AT)yahoo.com), Mar 11 2002
|
|
EXTENSIONS
|
G.f. proposed by Maksym Voznyy checked and corrected by R. J. Mathar, Sep 16 2009.
|
|
|
Search completed in 0.002 seconds
|
