A036359 Number of branched catafusenes with n condensed hexagons.

0, 0, 0, 1, 2, 12, 53, 250, 1115, 5012, 22032, 96746, 422732, 1848128, 8088090, 35498533, 156328706, 691192578, 3068780449, 13683070474, 61267204610, 275455737555, 1243320744572, 5633022679582, 25611815936218, 116840427373176, 534705818846660, 2454282243059471

Offset: 1

Author

N. J. A. Sloane

Keywords

• nonn

References

• F. Harary and R. C. Read, The Enumeration of Tree-like Polyhexes, Proc. Edinburgh Math. Soc., Series II, 17 (1970), pp. 1-13.
• Alexandru T. Balaban, The Enumeration of Cyclic Graphs, pp. 63-105 of A. T. Balaban, ed., Chemical Applications of Graph Theory, Ac. Press, 1976; see p. 75.

Crossrefs

Cf. A036359, A002216, A005963, A000228, A001998.

Formula

a(n) = A002216(n) - A001998(n-2) with A001998(-1)=1. - Sean A. Irvine, Oct 26 2020

Extensions

More terms from Sean A. Irvine, Oct 26 2020