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A057782
Building block is trapezoid formed from 3 equilateral triangles; sequence gives number of pieces (polytraps) that can be formed from n such trapezoids.
0
1, 9, 94, 1552, 27285, 509805, 9783124
OFFSET
1,2
COMMENTS
Also known as "Polytriamonds" because the building block is the unique triamond (composite of three equilateral triangles joined edge-to-edge). - Aaron N. Siegel, May 23 2022
REFERENCES
Computed by Brendan Owen.
CROSSREFS
KEYWORD
nonn,nice,hard,more
AUTHOR
N. J. A. Sloane, Oct 29 2000
EXTENSIONS
Link updated by William Rex Marshall, Dec 16 2009
a(7) from Aaron N. Siegel, May 23 2022
STATUS
approved