A007136 Number of symmetry sites in all planted 3-trees with n nodes. (Formerly M2493)

0, 0, 0, 1, 1, 3, 5, 14, 27, 65, 142, 338, 773, 1832, 4296, 10231, 24296, 58128, 139132, 334350, 804441, 1940239, 4685806, 11335797, 27455949, 66585170, 161646826

Offset

1,6

References

Bailey, C. K.; Fundamental orbits. Proceedings of the second West Coast conference on combinatorics, graph theory and computing (Eugene, Ore., 1983). Congr. Numer. 41 (1984), 149-152.

Bailey, C. K.; Palmer, E. M.; Kennedy, J. W.; Points by degree and orbit size in chemical trees. II. Discrete Appl. Math. 5 (1983), no. 2, 157-164.

R. W. Robinson, personal communication.

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

Links

Table of n, a(n) for n=1..27.

Index entries for sequences related to rooted trees

Index entries for sequences related to trees

Crossrefs

Sequence in context: A104208 A364314 A026777 * A145974 A147544 A192478

Adjacent sequences: A007133 A007134 A007135 * A007137 A007138 A007139

Keyword

nonn

Author

N. J. A. Sloane.

Status

approved