

A348095


Number of free npolysticks embedded in the square lattice with at least one cycle.


3



0, 0, 0, 1, 1, 10, 42, 254, 1331, 7358, 39543, 212911, 1135876, 6039878, 31975124, 168790048, 888664299, 4669177072
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OFFSET

1,6


COMMENTS

The number of holes h = e  v + 1 (e = the number of edges and v the number of vertices).  John Mason, Feb 12 2023


LINKS



FORMULA



EXAMPLE

The 4stick with a cycle is the unit square. The 5stick with a cycle is the unit square with one protruding edge. The 10 6sticks with a cycle are the unit square with two protruding edges (in various cis, meta, trans configurations) or with a protruding 2stick at various angles, or a 2x1 rectangle.
Size 6 examples 1 through 5:
++ ++ + + +++
       
++++ ++++ +++ +++ +++
   
++ ++
Examples 6 through 10:
+ ++ + + +++ +++
        
++ +++ +++ +++ +++
   
+++ ++


CROSSREFS



KEYWORD

nonn,more


AUTHOR



EXTENSIONS



STATUS

approved



