A181323 Number of ways of placing n rods of length 3 in a 3x3x3 cubic lattice without any two rods intersecting (0 <= n <= 9).

1, 27, 270, 1278, 3078, 3888, 2592, 918, 189, 21

Offset

0,2

Comments

This appears in relation to the degeneracy of the ground states of certain 3-dimensional lattice models in statistical physics.

Links

Table of n, a(n) for n=0..9.

Crossrefs

Row n=3 of A185697.

Sequence in context: A126548 A108670 A136925 * A136926 A042412 A078876

Adjacent sequences: A181320 A181321 A181322 * A181324 A181325 A181326

Keyword

fini,full,nonn

Author

Marcos Simoes, Jan 27 2011

Status

approved