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%I #17 Sep 20 2022 11:09:29
%S 1,1,6,90,3356,232283,27964488
%N Number of one-sided 'divisible' polyominoes of size 2^(n-1), where a 'divisible' polyomino is either a monomino (square) or a polyomino which can be separated into two identical 'divisible' polyominoes.
%C a(n) is nonzero for any n >= 1. Proof is trivial by induction.
%C a(n) <= A000988(2^(n-1)) as any polyomino counted here is also counted in A000988.
%e 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'.
%Y Cf. A000988.
%K nonn,more
%O 1,3
%A _Josh Marza_, May 30 2018
%E Definition changed and more terms added by _John Mason_, Sep 20, 2022
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