A194092 The number of biconnected squaregraphs with n vertices.

1, 1, 0, 1, 0, 1, 0, 2, 1, 5, 2, 17, 11, 65, 54, 299, 333, 1508, 2041, 8215, 12971

Offset: 1

Author

Don Knuth, Aug 15 2011

Keywords

• nonn
• hard
• more

Examples

			For n=11 the a(11)=2 solutions are the P pentomino and the 5-cogwheel.
The cases n=1 and n=2 are somewhat controversial, depending on whether the graphs K_1 and K_2 are considered to be "biconnected".
		

References

• See A194088

Links

• Don Knuth, squaregraph.w (CWEB program).

Crossrefs

Cf. A194088, A194089, A194090, A194091, A194093.

Programs

CWEB

(see Knuth link).