

A174313


Number of nstep walks on hexagonal lattice (no points repeated, no adjacent points unless consecutive in path).


6



1, 6, 18, 54, 162, 474, 1398, 4074, 11898, 34554, 100302, 290322, 839382, 2422626, 6984342, 20110806, 57851358, 166258242, 477419658, 1369878582, 3927963138, 11255743434, 32235116502, 92267490414, 263968559874, 754837708494, 2157584748150, 6164626128066, 17606866229010
(list;
graph;
refs;
listen;
history;
text;
internal format)



OFFSET

0,2


COMMENTS

The hexagonal lattice is the familiar 2dimensional lattice in which each point has 6 neighbors. This is sometimes called the triangular lattice.
Fisher and Hiley give 290334 and 839466 as their last terms instead of 290322 and 839382 (see A002933). Douglas McNeil confirms the correction on the seqfan list Nov 27 2010.


REFERENCES

N. J. A. Sloane, A Handbook of Integer Sequences, Academic Press, 1973 (includes this sequence).
N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).


LINKS



CROSSREFS

Cf. A173380 for square lattice equivalent.


KEYWORD

nonn,walk


AUTHOR



EXTENSIONS



STATUS

approved



