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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 (list; graph; refs; listen; history; text; internal format)
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), 1860-1871. 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), 1860-1871, 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

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Last modified August 14 07:04 EDT 2020. Contains 336477 sequences. (Running on oeis4.)