%I #16 Oct 10 2022 20:11:59
%S 0,1,1,1,1,2,3,4,4,6,10,11,16,18,33,34,56,56,110,106,193,177,372,335,
%T 662,571,1269,1084,2282,1875,4365,3568,7914,6257,15141,11935,27615,
%U 21170,52911,40486,96980,72490,186144,138981,342638,250814,658884,482029,1217327,875697,2345272,1686803
%N Number of n-celled polyominoes without holes, symmetric about axis 2.
%C In other words, free polyominoes, without holes, with both vertical and horizontal symmetries but no other. - _John Mason_, Oct 10 2022
%H Tomás Oliveira e Silva, <a href="http://sweet.ua.pt/tos/animals.html">Enumeration of polyominoes</a>
%Y Cf. A000104, A056877 (with holes allowed).
%K nonn
%O 1,6
%A _N. J. A. Sloane_, Sep 03 2000
%E a(29)-a(52) from _John Mason_, Oct 10 2022
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