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A359526
Number of unbiased (balanced) free polyiamonds with 2n cells.
0
1, 2, 10, 44, 283, 1922, 14163, 107771, 841846
OFFSET
1,2
COMMENTS
Define the bias of a polyiamond to be the difference between the number of black triangles and the number of white triangles when chessboard coloring is applied to the polyiamond. Unbiased polyiamonds are those having an equal number of black and white triangles. The sequence is defined for 2n rather than n as odd-sized polyiamonds are obviously biased.
CROSSREFS
Sequence in context: A105485 A151313 A144896 * A142983 A227852 A347524
KEYWORD
nonn,more
AUTHOR
John Mason, Jan 05 2023
STATUS
approved