

A121223


Number of degeneracies on the sets of ordinary trees with n vertices according to a topological index.


5



2, 2, 2, 11, 25, 98, 214, 747, 1947, 6399, 16846, 55131, 150720, 462160, 1302117
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OFFSET

7,1


COMMENTS

Konstantinova and Vidyuk compare various topological indices for their power to discriminate a large set of hexagonal, square and triangular lattice animals.
This here is an overview for the H_lambda^p index (a particular logarithmic weight over the layer matrix) for a test set of 11 ordinary trees (with n=7 vertices), 23 ordinary trees (with n= 8 vertices) etc. A "good" index is indicated by resulting in low degeneracies.


REFERENCES

Elena V. Konstantinova and Maxim V. Vidyuk, "Discriminating tests of information and topological indices. Animals and trees", J. Chem. Inf. Comput. Sci. 43 (2003), 18601871. See Table 15, column H_lambda^p.


LINKS

Table of n, a(n) for n=7..21.
Elena V. Konstantinova and Maxim V. Vidyuk, Discriminating tests of information and topological indices. Animals and trees, J. Chem. Inf. Comput. Sci. 43 (2003), 18601871, table 15, column 8.


EXAMPLE

For the test set of 7741 trees with n=15 vertices, the H_lambda^p index ended up in 1947 degeneracies.


CROSSREFS

Sequence in context: A289898 A068971 A019233 * A327559 A139518 A335986
Adjacent sequences: A121220 A121221 A121222 * A121224 A121225 A121226


KEYWORD

nonn


AUTHOR

Parthasarathy Nambi, Aug 20 2006


EXTENSIONS

Edited by R. J. Mathar, Mar 02 2009


STATUS

approved



