

A305324


Number of onesided 'divisible' polyominoes of size 2^(n1), where a 'divisible' polyomino is either a monomino (square) or a polyomino which can be separated into two identical 'divisible' polyominoes.


0




OFFSET

1,3


COMMENTS

a(n) is nonzero for any n >= 1. Proof is trivial by induction.
a(n) <= A000988(2^(n1)) as any polyomino counted here is also counted in A000988.


LINKS

Table of n, a(n) for n=1..7.


EXAMPLE

For n = 3 (polyominoes of size 4), the 'divisible' polyominoes are the I, O, J, L, S and Z tetrominoes. The T tetromino is not 'divisible'.


CROSSREFS

Cf. A000988.
Sequence in context: A232979 A218758 A219304 * A265088 A077370 A226382
Adjacent sequences: A305321 A305322 A305323 * A305325 A305326 A305327


KEYWORD

nonn,more


AUTHOR

Josh Marza, May 30 2018


EXTENSIONS

Definition changed and more terms added by John Mason, Sep 20, 2022


STATUS

approved



