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!)
A155354 Number of ways to place zero or more nonadjacent 2,0 3,1 4,2 4,3 4,4 5,2 6,2 polyhexes in any orientation on a planar nXnXn triangular grid. 0
1, 3, 7, 13, 21, 54, 165, 638, 2331, 9005, 38668, 204465, 1227713, 8257094, 59762784, 487017754, 4487006412, 47257428230, 557362552428 (list; graph; refs; listen; history; text; internal format)
OFFSET

6,2

LINKS

Table of n, a(n) for n=6..24.

EXAMPLE

Maximal 11 X 11 X 11 example

.............0

............0.0

...........0.0.1

..........0.0.1.0

.........1.1.1.0.0

........0.0.0.1.0.0

.......0.0.1.0.1.0.1

......0.0.1.0.0.0.1.0

.....1.1.1.0.1.1.1.0.0

....0.0.0.1.0.0.0.1.0.0

...0.0.0.0.1.0.0.0.1.0.0

CROSSREFS

Sequence in context: A147335 A147464 A146058 * A136219 A078582 A051336

Adjacent sequences:  A155351 A155352 A155353 * A155355 A155356 A155357

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 1 22:12 EST 2021. Contains 349435 sequences. (Running on oeis4.)