Abstract
A family (X, B 1), (X, B 2), …, (X, B q ) of q STS(υ)s is a λ-fold large set of STS(υ) and denoted by LSTS λ (υ) if every 3-subset of X is contained in exactly λ STS(υ)s of the collection. It is indecomposable and denoted by IDLSTS λ (υ) if there does not exist an LSTSλ′(υ) contained in the collection for any λ′ < λ. In this paper, we show that for λ = 5, 6, there is an IDLSTS λ (υ) for υ ≡ 1 or 3 (mod 6) with the exception IDLSTS6(7).
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Supported by National Natural Science Foundation of China (Grant Nos. 10971051 and 11071056)
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Cheng, M.H., Tian, Z.H. Indecomposable large sets of Steiner triple systems with indices 5, 6. Acta. Math. Sin.-English Ser. 28, 2169–2184 (2012). https://doi.org/10.1007/s10114-012-0693-z
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DOI: https://doi.org/10.1007/s10114-012-0693-z