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A377309
Number of stones-and-bones tilings of an n-triangle.
0
1, 0, 1, 3, 0, 30, 246, 0, 25321, 591103, 0, 603105309, 41333676318, 0, 410382321560202, 83918368144461643, 0, 8025244898075570226296, 4941312847984149589980261
OFFSET
0,4
COMMENTS
These numbers were computed using the TilingCount program of David Desjardins. Stones are also called T_2 tiles and bones are also called L_3 tiles.
FORMULA
a(n)=0 when n is congruent to 1 mod 3, since in that case the number of cells in the n-triangle is not divisible by 3.
EXAMPLE
For n=3 the three tilings are
A
A A
B B B
and
A
A B
A B B
and
A
B A
B B A
CROSSREFS
Cf. A334875.
Sequence in context: A215680 A007415 A145222 * A058833 A368284 A266168
KEYWORD
nonn,more
AUTHOR
James Propp, Oct 23 2024
STATUS
approved