A121119 Related to enumeration of rooted catapolyoctagons (see Cyvin reference for precise definition).

0, 0, 0, 1, 2, 12, 24, 113, 232, 1008, 2122, 8891, 19110, 78540, 171694, 697700, 1546552, 6240064, 13992408, 56192581, 127231246, 509314256, 1162747842, 4644046225, 10677793584

Offset

1,5

References

S. J. Cyvin, B. N. Cyvin, and J. Brunvoll. Enumeration of tree-like octagonal systems: catapolyoctagons, ACH Models in Chem. 134 (1997), 55-70.

Links

Table of n, a(n) for n=1..25.

Formula

a(n) = A121118(n+1) -A121118(n) -2*A036759(n+1) +A036759(n) +4*A036758(n/2) [Cyvin eq. (44)], where A(.) is zero for non-integer indices. - R. J. Mathar, Jul 31 2019

Crossrefs

Sequence in context: A224923 A247086 A337077 * A226899 A309278 A052565

Adjacent sequences: A121116 A121117 A121118 * A121120 A121121 A121122

Keyword

nonn

Author

N. J. A. Sloane, Aug 13 2006

Status

approved