OFFSET
1,3
COMMENTS
No tiling is symmetric to both the x- and the y-axis.
No tiling is symmetric to an oblique symmetry axis of the diamond.
If a tiling is symmetric to the x-axis then a reflection over the y-axis is equal to a rotation by 180 degrees.
The number of tilings is 4 * a(n) if rotations are counted as distinct.
All tilings have exactly the minimum number of square tetrominoes given by ceiling(n/2).
LINKS
James Propp, A Pedestrian Approach to a Method of Conway, or, A Tale of Two Cities, Mathematics Magazine, Vol. 70, No. 5 (Dec., 1997), 327-340.
Walter Trump, Axially symmetric Aztec diamond tilings
CROSSREFS
KEYWORD
nonn
AUTHOR
Walter Trump, Apr 21 2021
STATUS
approved