

A365995


Number of free polyominoids with n cells, allowing flat cornerconnections and rightangled edgeconnections.


17




OFFSET

1,2


COMMENTS

This sequence and the related sequences A365650A365655 and A365996A366010 count polyominoids (A075679) with different rules for how the cells can be connected. In these sequences, connections other than the specified ones are permitted, but the polyominoids must be connected through the specified connections only. The polyominoids counted by this sequence, for example, are allowed to have rightangled cornerconnections and flat edgeconnections, as long as they are not needed for the polyominoid to be connected. A connection is flat if the two neighboring cells lie in the same plane, otherwise it is rightangled.


LINKS



CROSSREFS

The following table lists counting sequences for free, fixed, and onesided polyominoids with different sets of allowed connections. "" means flat connections and "L" means rightangled connections.
cornerconnections  edgeconnections  free  fixed  1sided
++++


KEYWORD

nonn,hard,more


AUTHOR



STATUS

approved



