login
This site is supported by donations to The OEIS Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A259863 Number of rooted highly irregular trees with n nodes. 4
1, 1, 0, 2, 0, 0, 0, 4, 9, 5, 0, 0, 0, 7, 15, 16, 34, 72, 133, 250, 399, 572, 828, 1176, 1700, 2509, 3456, 4494, 5887, 7980, 11625, 18064, 28710, 46665, 77070, 127187, 209300, 341674, 550078, 873272 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,4

REFERENCES

K. A. McKeon, Letter to N. J. A. Sloane, Jul 25 1991. Gives a(n) for n <= 40.

LINKS

Table of n, a(n) for n=1..40.

Alavi, Yousef, Gary Chartrand, Fan RK Chung, Paul Erdős, Ronald L. Graham, and Ortrud R. Oellermann, Highly irregular graphs, Journal of Graph Theory, 11, no. 2 (1987): 235-249.

CROSSREFS

Cf. A259864.

Sequence in context: A280292 A181566 A110173 * A283666 A131427 A153198

Adjacent sequences:  A259860 A259861 A259862 * A259864 A259865 A259866

KEYWORD

nonn,more

AUTHOR

N. J. A. Sloane, Jul 08 2015

STATUS

approved

Lookup | Welcome | Wiki | Register | Music | Plot 2 | Demos | Index | Browse | More | WebCam
Contribute new seq. or comment | Format | Style Sheet | Transforms | Superseeker | Recent
The OEIS Community | Maintained by The OEIS Foundation Inc.

License Agreements, Terms of Use, Privacy Policy. .

Last modified July 20 01:05 EDT 2019. Contains 325168 sequences. (Running on oeis4.)