A066865 Number of binary arrangements without adjacent 1's on n X n staggered hexagonal torus bent for odd n.

1, 5, 22, 217, 4726, 164258, 14840533, 1834600977, 669877863205, 296979228487760, 434542100979981567, 692625866382651263578, 4053364289624915167879497, 23237986479606982160703729647, 543749373021017146939376423644362, 11213018647250714014261414954480048385

Offset: 1

Author

R. H. Hardin, Jan 25 2002

Keywords

• nonn

Examples

			Neighbors for n=4:
\|/ | \|/ |
-o--o--o--o-
 | /|\ | /|\
\|/ | \|/ |
-o--o--o--o-
 | /|\ | /|\
\|/ | \|/ |
-o--o--o--o-
 | /|\ | /|\
\|/ | \|/ |
-o--o--o--o-
 | /|\ | /|\
Neighbors for n=5:
\|/ | \|/ | \|/
 o--o--o--o--o
/| /|\ | /|\ |\
\|/ | \|/ | \|/
 o--o--o--o--o
/| /|\ | /|\ |\
\|/ | \|/ | \|/
 o--o--o--o--o
/| /|\ | /|\ |\
\|/ | \|/ | \|/
 o--o--o--o--o
/| /|\ | /|\ |\
\|/ | \|/ | \|/
 o--o--o--o--o
/| /|\ | /|\ |\
		

References

• Steven R. Finch, Mathematical Constants, Cambridge, 2003, pp. 342-349.
• J. Katzenelson and R. P. Kurshan, S/R: A Language for Specifying Protocols and Other Coordinating Processes, pp. 286-292 in Proc. IEEE Conf. Comput. Comm., 1986.

Links

• Steven R. Finch, Hard Square Entropy Constant [Broken link]
• Steven R. Finch, Hard Square Entropy Constant [From the Wayback machine]

Crossrefs

Cf. A006506, A027683, A066863, A066864, A066866, A067967 (shifted instead of bent).

Row sums of A067015.

Extensions

More terms from Sean A. Irvine, Nov 18 2023