An upper approximation to the BIBD (15, 21, 7, 5, 2)
نویسندگان
چکیده
The design (15,21,7,5,2) is the only BIBD of block size 5 that does not exist. If it did exist, it would provide an exact bicovering, in 21 blocks of size 5, of the pairs from 15 points. However, we show that 22 quintuples are sufficient to provide a bicover of the pairs from 15 points; thus there are only 10 repetitions required in the bicovering.
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ورودعنوان ژورنال:
- Australasian J. Combinatorics
دوره 2 شماره
صفحات -
تاریخ انتشار 1990