|
Search: id:A112840
|
|
|
| A112840 |
|
Large-number statistic from the enumeration of domino tilings of a 7-pillow of order n. |
|
+0
3
|
|
| 1, 1, 1, 1, 1, 2, 3, 7, 11, 28, 51, 154, 389, 1556, 4833, 22477, 80532, 440512, 1916580, 13388593, 73763989, 632754664, 4175659899, 42606281476, 336819337955, 4181786155008, 40981322633555, 630857431556758, 7576627032674784
(list; graph; listen)
|
|
|
OFFSET
|
0,6
|
|
|
COMMENT
|
A 7-pillow is a generalized Aztec pillow. The 7-pillow of order n is a rotationally-symmetric region. It has a 2 X 2n central band of squares and then steps up from this band with steps of 7 horizontal squares to every 1 vertical square and steps down with steps of 1 horizontal square to every 1 vertical square.
|
|
REFERENCES
|
C. Hanusa (2005). A Gessel-Viennot-Type Method for Cycle Systems with Applications to Aztec Pillows. PhD Thesis. University of Washington, Seattle, USA.
|
|
EXAMPLE
|
The number of domino tilings of the 7-pillow of order 8 is 23353=11^2*193. A112840(n)=11.
|
|
CROSSREFS
|
A112839 breaks down as A112840^2 times A112841, where A112841 is not necessarily square-free.
3-pillows: A112833-A112835; 5-pillows: A112836-A112838; 9-pillows: A112842-A112844.
Sequence in context: A107857 A107858 A143926 this_sequence A014981 A096362 A005479
Adjacent sequences: A112837 A112838 A112839 this_sequence A112841 A112842 A112843
|
|
KEYWORD
|
nonn
|
|
AUTHOR
|
Christopher Hanusa (chanusa(AT)math.binghamton.edu), Sep 21 2005
|
|
|
Search completed in 0.002 seconds
|
