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

1,5

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.

Links

Table of n, a(n) for n=1..28.

Formula

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

Crossrefs

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

Sequence in context: A218782 A007225 A139046 * A055703 A242513 A006738

Adjacent sequences: A036356 A036357 A036358 * A036360 A036361 A036362

Keyword

nonn

Author

N. J. A. Sloane.

Extensions

More terms from Sean A. Irvine, Oct 26 2020

Status

approved