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

 

Logo

Year-end appeal: Please make a donation to the OEIS Foundation to support ongoing development and maintenance of the OEIS. We are now in our 56th year, we are closing in on 350,000 sequences, and we’ve crossed 9,700 citations (which often say “discovered thanks to the OEIS”).

Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A155375 Number of ways to place zero or more nonadjacent 0,0 1,0 2,0 2,1 3,0 4,0 4,1 5,0 polyhexes in any orientation on a planar nXnXn triangular grid. 0
1, 4, 13, 37, 146, 614, 2467, 11092, 69586, 500162, 4040869, 39876354, 445952771 (list; graph; refs; listen; history; text; internal format)
OFFSET

5,2

LINKS

Table of n, a(n) for n=5..17.

EXAMPLE

Maximal 9 X 9 X 9 example

...........1

..........0.1

.........0.1.1

........1.0.0.1

.......1.0.0.1.1

......1.1.0.0.0.1

.....1.0.0.0.0.0.0

....1.1.0.0.1.0.1.0

...1.0.0.1.1.1.1.1.1

CROSSREFS

Sequence in context: A091874 A297391 A108489 * A155307 A155344 A155418

Adjacent sequences:  A155372 A155373 A155374 * A155376 A155377 A155378

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 22 2009

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 December 3 21:17 EST 2021. Contains 349468 sequences. (Running on oeis4.)