[seqfan] Smeared polyominoes
acwacw at gmail.com
Sun Sep 16 03:21:46 CEST 2018
The number of polyominoes of order n which possess an axis along which
every cell has a neighbor. The straight tromino works, for example, but the
L-tromino does not, because along both the X and Y axes, there is one cell
with no neighbors on either side
My hand calculation, for n ranging from 1 to 7: 0,1,1,3,3,9,16; this is
already not in OEIS.
I'm not creating an entry in OEIS yet, because these are just hand-counted
(from looking at exhaustive sets of polyominoes at Wikipedia). Can somebody
who has decent polyomino-handling software verify these values, and maybe
give a few more? I'm going cross-eyed already.
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