%I #9 Jun 04 2022 19:39:42
%S 1,7,42,193,853,3553,14564,58636,234523
%N Number of rotationally symmetric 2n-celled polyominoes with 1 hole.
%H Tomás Oliveira e Silva, <a href="http://sweet.ua.pt/tos/animals.html">Enumeration of polyominoes</a>
%Y Cf. A056883.
%K nonn,more
%O 5,2
%A _N. J. A. Sloane_, Sep 05 2000
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