Nonexistence of Almost Moore Digraphs of Diameter Four
نویسندگان
چکیده
Regular digraphs of degree d > 1, diameter k > 1 and order N(d, k) = d+· · ·+dk will be called almost Moore (d, k)-digraphs. So far, the problem of their existence has only been solved when d = 2, 3 or k = 2, 3. In this paper we prove that almost Moore digraphs of diameter 4 do not exist for any degree d.
منابع مشابه
On the nonexistence of almost Moore digraphs of diameter four
Almost Moore digraphs appear in the context of the degree/diameter problem as a class of extremal directed graphs, in the sense that their order is one less than the unattainable Moore bound M(d, k) = 1 + d + · · · + d, where d > 1 and k > 1 denote the maximum out-degree and diameter, respectively. So far, the problem of their existence has only been solved when d = 2, 3 or k = 2, 3. In this pa...
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ورودعنوان ژورنال:
- Electr. J. Comb.
دوره 20 شماره
صفحات -
تاریخ انتشار 2013