OFFSET
0,2
LINKS
Alois P. Heinz, Table of n, a(n) for n = 0..484
Wikipedia, Domino (mathematics).
Wikipedia, Tromino.
EXAMPLE
a(1) = 4:
._. ._. ._. ._.
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CROSSREFS
KEYWORD
nonn
AUTHOR
Alois P. Heinz, Jul 30 2023
STATUS
approved