OFFSET
1,10
LINKS
Christopher Hunt Gribble, C++ program
FORMULA
EXAMPLE
The triangle is:
n\k 1 2 3 4 5 6 7 8 ...
.
0 0 0 0 0 0 0 0 0 ...
1 0 0 0 0 0 0 0 ...
2 1 1 3 4 9 13 ...
3 4 3 9 9 21 ...
4 15 38 68 160 ...
5 75 77 311 ...
6 604 2384 ...
7 4556 ...
...
T(3,5) = 3 because there are 3 different sets of 2 tilings of the 3 X 5 rectangle by integer-sided squares, where any sequence of group D2 operations will transform each tiling in a set into the other in the same set. Group D2 operations are:
. the identity operation
. rotation by 180 degrees
. reflection about a horizontal axis through the center
. reflection about a vertical axis through the center
An example of a tiling in each set is:
._________. ._________. ._________.
| |_| | | |_|_|_| | |_|_|
|_ _|_|_ _| |___|_| | | |_|_|
|_|_|_|_|_| |_|_|_|___| |_____|_|_|
CROSSREFS
KEYWORD
AUTHOR
Christopher Hunt Gribble, Jul 22 2013
STATUS
approved