login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A067967 Number of binary arrangements without adjacent 1's on n X n hexagonal staggered torus shifted for odd n. 1
1, 5, 19, 217, 4076, 164258, 12285477, 1834600977, 527717587843, 296979228487760, 324881629286870822, 692625866382651263578 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

REFERENCES

Steven R. Finch, Mathematical Constants, Cambridge, 2003, pp. 342-349.

LINKS

Table of n, a(n) for n=1..12.

Steven R. Finch, Hard Square Entropy Constant [Broken link]

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

EXAMPLE

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-

: | /|\ | /|\ |\

CROSSREFS

For bent instead of shifted for odd n see A066865.

Sequence in context: A058765 A317340 A328716 * A092751 A122150 A092663

Adjacent sequences:  A067964 A067965 A067966 * A067968 A067969 A067970

KEYWORD

nonn

AUTHOR

R. H. Hardin, Feb 02 2002

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified June 1 23:14 EDT 2020. Contains 334765 sequences. (Running on oeis4.)