OFFSET
7,3
COMMENTS
The sequence refers to polyominoes with one hole and precisely one diagonal symmetry. - John Mason, Jan 16 2023
LINKS
Tomás Oliveira e Silva, Enumeration of polyominoes
CROSSREFS
KEYWORD
nonn
AUTHOR
N. J. A. Sloane, Sep 05 2000
EXTENSIONS
a(29)-a(49) from John Mason, Jan 16 2023
STATUS
approved