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The Spectrum of Orthogonal Steiner Triple Systems

Published online by Cambridge University Press:  20 November 2018

Charles J. Colbourn
Affiliation:
Combinatorics and Optimization University of Waterloo Waterloo, Ontario N2L 3G1
Peter B. Gibbons
Affiliation:
Computer Science University of Auckland Auckland New Zealand
Rudolf Mathon
Affiliation:
Computer Science University of Toronto Toronto, Ontario M5S I A4
Ronald C. Mullin
Affiliation:
Combinatorics and Optimization University of Waterloo Waterloo, Ontario N2L 3G1
Alexander Rosa
Affiliation:
Mathematics and Statistics McMaster University Hamilton, Ontario L8S4K1
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Abstract

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Two Steiner triple systems (V, 𝓑) and (V, 𝓓) are orthogonal if they have no triples in common, and if for every two distinct intersecting triples {x,y,z} and {x, y, z} of 𝓑, the two triples {x,y,a} and {u, v, b} in (𝓓 satisfy a ≠ b. It is shown here that if v ≡ 1,3 (mod 6), v ≥ 7 and v ≠ 9, a pair of orthogonal Steiner triple systems of order v exist. This settles completely the question of their existence posed by O'Shaughnessy in 1968.

Keywords

Type
Research Article
Copyright
Copyright © Canadian Mathematical Society 1994

References

1. Dinitz, J. H. and Stinson, D. R., Contemporary Design Theory: A Collection of Surveys, Wiley, New York, 1992.Google Scholar
2. Gibbons, R. B., A census of orthogonal Steiner triple systems of order 15, Annals Discrete Math. 26(1987), 165182.Google Scholar
3. Gibbons, R. B. and Mathon, R. A., The use of hill-climbing to construct orthogonal Steiner triple systems, J. Combin. Designs, to appear.Google Scholar
4. Greig, M., Designs from projective planes, and PBD bases, preprint, 1992.Google Scholar
5. MacNeish, H. F., Euler squares, Ann. Math. 23(1922), 221227.Google Scholar
6. Mullin, R. C. and Nemeth, E., On furnishing Room squares, J. Combin. Theory 7(1969), 266272.Google Scholar
7. Mullin, R. C. and Nemeth, E., On the nonexistence of orthogonal Steiner systems of order 9, Canad. Math. Bull. 13(1970), 131134.Google Scholar
8. Mullin, R. C. and Stinson, D. R., Pairwise balanced designs with block sizes 6t + 1, Graphs Combin. 3(1987), 365377.Google Scholar
9. O'Shaughnessy, C. D., A Room design of order 14, Canad. Math. Bull. 11(1968), 191194.Google Scholar
10. Rosa, A., On the falsity of a conjecture on orthogonal Steiner triple systems, J. Combin. Theory Sen A 16(1974), 126128.Google Scholar
11. Stinson, D. R. and Zhu, L., Orthogonal Steiner triple systems of order 6t + 3, Ars Combin. 31(1991), 3364.Google Scholar
12. Wilson, R. M., Constructions and uses of pairwise balanced designs, Math. Centre Tracts 55(1974), 1841.Google Scholar