A045909 Number of unsymmetrical catafusenes with n hexagons (see reference for precise definition).

0, 0, 1, 8, 39, 190, 861, 3943, 17867, 81496, 372378, 1709842, 7879360, 36454004, 169239651, 788311290, 3683018475, 17255646688, 81056033636, 381668479192, 1801188588566, 8517994717214, 40360814900566, 191589547228523, 911009396044132, 4338777661726040

Offset

0,4

Comments

Column C_s of Table 6 in Cyvin et al. Computed by subtracting all the other symmetry classes from the total. - Sean A. Irvine, Mar 27 2021

Links

Table of n, a(n) for n=0..25.

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) = A045906(n) - A045907(n) - A045908(n/2) - A342554(n/2) - A342570(n/2) - 2*A030529(n/4) - A055879(n/4) - [n=0] with sequences assumed to be 0 for non-integer arguments. - Sean A. Irvine, Mar 27 2021

Crossrefs

Cf. A045906, A045907, A045908, A342554, A342570, A030529, A055879.

Sequence in context: A097787 A215731 A144414 * A264091 A353211 A319362

Adjacent sequences: A045906 A045907 A045908 * A045910 A045911 A045912

Keyword

nonn

Author

N. J. A. Sloane

Extensions

More terms from Sean A. Irvine, Mar 27 2021

Status

approved