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%I #8 Jun 14 2024 12:16:33
%S 0,0,0,0,1,1,0,0,4,6,2,0,17,29
%N Number of free n-celled polyominoes to which two inequivalent cells can be adjoined such that the two resulting free (n+1)-celled polyominoes are identical.
%C Two cells that can be adjoined to an n-celled polyomino are equivalent if there is an isomorphism between the two resulting (n+1)-celled polyominoes that maps the adjoined cell of the first to the adjoined cell of the second.
%H Pontus von Brömssen, <a href="/A373635/a373635.svg">Illustration up to n = 11</a>.
%H <a href="/index/Pol#polyominoes">Index entries for sequences related to polyominoes</a>.
%e The smallest example is the P pentomino shown below. The two free hexominoes obtained by adjoining one of the two cells marked "*" are identical, but there is no isomorphism between them that also maps the marked cell of the first to the marked cell of the second.
%e _ _
%e *| |
%e | _|*
%e |_|
%Y Cf. A255890, A367758, A373636, A373637.
%K nonn,more
%O 1,9
%A _Pontus von Brömssen_, Jun 13 2024