A153982 - OEIS

The OEIS is supported by the many generous donors to the OEIS Foundation.

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 61st year, we have over 378,000 sequences, and we’ve reached 11,000 citations (which often say “discovered thanks to the OEIS”).

Other ways to Give

A153982

Number of planar n X n X n binary triangular grids symmetric under 120 degree rotation with every one adjacent to exactly 1 other one.

1, 1, 1, 1, 3, 6, 11, 30, 72, 201, 747, 2553, 10966, 58566, 287270, 1751705, 13247679, 91522060, 788765512, 8490555128, 84280981845, 1040689637617, 15976611935513, 225667587813248, 3966856029530488, 86787076062074170, 1745622351406501121

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,5

LINKS

Table of n, a(n) for n=0..26.

CROSSREFS

Sequence in context: A109781 A360888 A101958 * A119367 A079801 A280259

Adjacent sequences: A153979 A153980 A153981 * A153983 A153984 A153985

KEYWORD

nonn

AUTHOR

R. H. Hardin Jan 04 2009

STATUS

approved