A045908 - OEIS

A045908

Number of catafusenes with C_{2v}(b) symmetry (see reference for precise definition).

0, 1, 3, 13, 49, 203, 833, 3533, 15133, 65891, 289865, 1288491, 5774847, 26076165, 118501583, 541605705, 2487893725, 11480052755, 53188676889, 247337349095, 1154007818323, 5400694067345, 25345508567027, 119251934995963, 562414480094339, 2658260322324013

(list; graph; refs; listen; history; text; internal format)

OFFSET

0,3

COMMENTS

Column C_{2v}(b) in Table 6 and Eq. (53) in Cyvin. - Sean A. Irvine, Mar 26 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) = (1/2) * (b(n+1) - b(n) - b(n/2)) where b(n)=A002212(n) is understood to be 0 for noninteger arguments. - Sean A. Irvine, Mar 26 2021

CROSSREFS

Cf. A002212.