A373635 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.
0, 0, 0, 0, 1, 1, 0, 0, 4, 6, 2, 0, 17, 29
Offset: 1
Examples
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.
_ _
*| |
| _|*
|_|
Links
- Pontus von Brömssen, Illustration up to n = 11.
- Index entries for sequences related to polyominoes.
Comments