Independent sets in Steiner triple systems
نویسندگان
چکیده
A set of points in a Steiner triple system (STS(v)) is said to be independent if no three of these points occur in the same block. In this paper we derive for each k ≤ 8 a closed formula for the number of independent sets of cardinality k in an STS(v). We use the formula to prove that every STS(21) has an independent set of cardinality eight and is as a consequence 4-colourable. AMS classification: 05B07
منابع مشابه
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عنوان ژورنال:
- Ars Comb.
دوره 72 شماره
صفحات -
تاریخ انتشار 2004