OFFSET
7,2
LINKS
A. J. Guttmann and A. R. Conway, Hexagonal lattice directed site animals, Statistical Physics on the Eve of the Twenty-First Century, ed. M. T. Batchelor, World Scientific, 1999 (H_7 for hexagonal lattices Table 1).
FORMULA
G.f.: x^7*B(x)/((1-x)^15*(1+x)^7*(1+x^2)^6*(1+x^2+x^4)^4*(1+x^4)^2) where B(x) is g.f. of A055916.
CROSSREFS
KEYWORD
nonn
AUTHOR
Christian G. Bower, Jun 22 2000
STATUS
approved