A139772 Number of linear trimer coverings of a 3n X 3n square.

2, 64, 37160, 378875648, 67433401509980, 209087783283413477232, 11281654633785546173131745084

Offset

1,1

References

J. Van Craen, The residual entropy of rectilinear trimers on the square lattice at close packing, J. Chem. Phys. 63 (1975) 2591-2596.

Links

Table of n, a(n) for n=1..7.

Crossrefs

Cf. A004003.

Sequence in context: A155957 A085535 A060613 * A348214 A092238 A228252

Adjacent sequences: A139769 A139770 A139771 * A139773 A139774 A139775

Keyword

nonn,more

Author

Steven Finch, May 20 2008

Extensions

Name corrected and a(6)-a(7) from Andrew Howroyd, Feb 16 2022

Status

approved