A045909 -id:A045909 - cp's OEIS frontend

A342554 Number of catafusenes with 2n hexagons and C symmetry.

0, 0, 1, 5, 22, 97, 408, 1752, 7535, 32895, 144816, 644058, 2886967, 13037352, 59248959, 270799903, 1243939278, 5740014143, 26594306442, 123668622726, 577003771681, 2700346810482, 12672753684799, 59625966523555, 281207237408728, 1329130156859362

Offset: 0

Sean A. Irvine, Mar 27 2021

nonn

Column C in Table 6 and Eq. (52) in Cyvin et al.

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.

Cf. A045906, A045907, A045908, A045909, A342570.

a(n) = (1/4) * (A002212(n+1) - A002212(n) - A039658(n)) - (1/2) * (A055879(n) + A002212(n/2) - A055879(n/2)) where sequences are assumed 0 for non-integer arguments.

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

Original entry on oeis.org

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

Sean A. Irvine, Mar 27 2021

nonn

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

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.

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

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

cp's OEIS Frontend

A342554 Number of catafusenes with 2n hexagons and C symmetry.

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