A121116 Related to enumeration of rooted catapolyoctagons (see Cyvin reference for precise definition).

0, 0, 1, 15, 168, 1703, 16539, 157416, 1483900, 13928238, 130547475, 1223803350, 11484513612, 107940809223, 1016351200410, 9588249961074, 90633332095992, 858386837556696, 8145257860480545, 77432954101974513, 737419153249761752, 7034562802431438771, 67214038308803342715

Offset

1,4

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, Table III, X_r.

Links

Table of n, a(n) for n=1..23.

Formula

a(n) = Sum_{i=1..n-2} A036758(i)*A121115(n-i). [Cyvin eq. (19)]. - R. J. Mathar, Jul 31 2019

Crossrefs

Sequence in context: A160197 A055660 A121114 * A218928 A202663 A202123

Adjacent sequences: A121113 A121114 A121115 * A121117 A121118 A121119

Keyword

nonn

Author

N. J. A. Sloane, Aug 13 2006

Status

approved