A194093 The number of labeled biconnected squaregraphs with n vertices.

1, 1, 0, 1, 0, 3, 0, 12, 2, 55, 22, 278, 182, 1506, 1378, 8595, 10040, 51134, 71814, 314693, 509200

Offset: 1

Author

Don Knuth, Aug 15 2011

Keywords

• nonn
• hard
• more

Examples

			[See A194089 for the definition of "labeling".] For n=11 the P-pentomino can be labeled in 20 ways; the 5-cogwheel in only 2; hence a(11)=22.
The values of a(1) and a(2) depend on whether or not one believes that
the small complete graphs K_1 and K_2 respectively are biconnected.
		

References

• See A194088

Links

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

Crossrefs

Cf. A194088, A194089, A194090, A194091, A194092.

Programs

CWEB

(see Knuth link).