A122672 Number of primitive coronoid systems with n hexagons.

1, 1, 3, 2, 11, 12, 40, 68, 192, 395, 1061, 2432, 6318, 15417, 39660, 99550, 256388, 654003, 1689973, 4355457, 11305165, 29347706, 76527893

Offset

8,3

Links

Table of n, a(n) for n=8..30.

S. J. Cyvin et al., The simplest coronoids: hollow hexagons, Struct. Chem., 2 (1991), 555-566.

Johan Nilsson, Illustrations for initial terms

Crossrefs

Sequence in context: A159610 A074246 A134426 * A194608 A297870 A052973

Adjacent sequences: A122669 A122670 A122671 * A122673 A122674 A122675

Keyword

nonn,more

Author

N. J. A. Sloane, Sep 23 2006

Extensions

a(15)-a(30) from Johan Nilsson, Aug 12 2015

Status

approved