OFFSET
1,2
COMMENTS
LINKS
EXAMPLE
For n = 2, the four polyominoes are the 1 X 1, 1 X 2, and 2 X 2 squares or rectangles, and the 3-celled L-shape. - N. J. A. Sloane, Jan 21 2021
CROSSREFS
KEYWORD
nonn,more
AUTHOR
John Mason, Feb 04 2016
EXTENSIONS
A value for a(6) was submitted by Sam Vodovoz on Aug 02 2020 but this was retracted via email on Aug 03 2020. - N. J. A. Sloane, Aug 03 2020
a(5) corrected by Talmon Silver, Sep 24 2020
a(6) from Talmon Silver, Oct 01 2020
Added "free" to definition. - N. J. A. Sloane, Jan 21 2021
STATUS
approved