Hostname: page-component-848d4c4894-sjtt6 Total loading time: 0 Render date: 2024-07-05T18:20:58.083Z Has data issue: false hasContentIssue false

Perfect codes in the graphs Ok and L(Ok)

Published online by Cambridge University Press:  18 May 2009

D. H. Smith
Affiliation:
Polytechnic of Wales, Pontypridd, Wales
Rights & Permissions [Opens in a new window]

Extract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

In [6] the question of the existence of perfect e-codes in the infinite family of distance-transitive graphs Ok was considered. It was pointed out that it is difficult to rule out completely any particular value of [6] because of the difficulty of working with the sphere packing condition. For e = 1, 2, 3 it can be seen from the results of [6] that the condition given by the generalisation of Lloyd's theorem is satisfied for infinitely many values of k. We shall show that this is not the case for e = 4 and we shall prove that there are no perfect 4-codes in Ok.

Type
Research Article
Copyright
Copyright © Glasgow Mathematical Journal Trust 1980

References

REFERENCES

1.Baker, A. and Davenport, H., The equations 3x2 - 2 = y2 and 8x2 - 7 = z2, Quart. J. Math. Oxford (2), 20 (1969), 129137.Google Scholar
2.Biggs, N. L., Algebraic Graph Theory Cambridge Math. Tracts No. 67, (Cambridge University Press, London, 1974).Google Scholar
3.Biggs, N. L., Perfect codes and distance-transitive graphs, in “Combinatorics” (Proceedings of the British Combinatorial Conference, 1973) (Cambridge University Press, London/New York 1974), 18.Google Scholar
4.Biggs, N. L., Perfect codes in graphs, J. Combinatorial Theory, Ser. B 15 (1973), 289296.Google Scholar
5.Hammond, P., q-coverings, codes and line graphs (to appear).Google Scholar
6.Hammond, P. and Smith, D. H., Perfect codes in the graphs Ok. J. Combinatorial Theory, Ser. B 19 (1975), 239255.Google Scholar