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A007136 Number of symmetry sites in all planted 3-trees with n nodes.
(Formerly M2493)
0
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 (list; graph; refs; listen; history; text; internal format)
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: A295359 A104208 A026777 * A145974 A147544 A192478

Adjacent sequences:  A007133 A007134 A007135 * A007137 A007138 A007139

KEYWORD

nonn

AUTHOR

N. J. A. Sloane.

STATUS

approved

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Last modified August 14 22:45 EDT 2022. Contains 356122 sequences. (Running on oeis4.)