login
The OEIS Foundation is supported by donations from users of the OEIS and by a grant from the Simons Foundation.

 

Logo


Hints
(Greetings from The On-Line Encyclopedia of Integer Sequences!)
A098852 Number of triangle-free self-dual configurations of type (n_3). 3
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0, 1, 2, 6, 40, 307 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,18

LINKS

Table of n, a(n) for n=1..21.

A. Betten, G. Brinkmann and T. Pisanski, Counting symmetric configurations v_3, Discrete Appl. Math., 99 (2000), 331-338.

CROSSREFS

Cf. A001403, A100001, A023994.

Sequence in context: A337071 A098854 A056787 * A274482 A274277 A120592

Adjacent sequences:  A098849 A098850 A098851 * A098853 A098854 A098855

KEYWORD

nonn,hard,more

AUTHOR

N. J. A. Sloane, Nov 05 2004

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 September 21 20:10 EDT 2021. Contains 347598 sequences. (Running on oeis4.)