A342570 Number of catafusenes with 2n hexagons and D_{2h}(a) symmetry.

0, 1, 1, 3, 4, 9, 13, 29, 46, 101, 167, 375, 644, 1461, 2563, 5899, 10534, 24469, 44237, 103643, 189302, 446381, 821905, 1948853, 3612868, 8605289, 16044151, 38362199, 71877226, 172423769, 324440379, 780496109, 1474118424, 3554991269, 6736507309, 16281079899

Offset

0,4

Comments

Column D_{2h}(a) in Table 6 and Eq. (51) in Cyvin et al.

Links

Table of n, a(n) for n=0..35.

S. J. Cyvin, B. N. Cyvin, J. Brunvoll and E. Brendsdal, Enumeration and Classification of Certain Polygonal Systems Representing Polycyclic Conjugated Hydrocarbons: Annelated Catafusenes, Journal of Chemical Information and Modeling [formerly, J. Chem. Inform. Comput. Sci.], 34 (1994), pp. 1174-1180.

Formula

a(n) = A055879(n) + (1/2) * (A039658(n) - A055879(n/2)) where A055879 is 0 for non-integer arguments.

Crossrefs

Cf. A045906, A045907, A045908, A045909, A342554.

Sequence in context: A056514 A151517 A219043 * A050163 A207016 A333333

Adjacent sequences: A342567 A342568 A342569 * A342571 A342572 A342573

Keyword

nonn

Author

Sean A. Irvine, Mar 27 2021

Status

approved