Abstract
Given n and d, we describe the structure of trees with the maximal possible number of greatest independent sets in the class of n-vertex trees of vertex degree at most d.We show that the extremal tree is unique for all even n but uniqueness may fail for odd n; moreover, for d = 3 and every odd n ≥ 7, there are exactly ⌈(n − 3)/4⌉ + 1 extremal trees. In the paper, the problem of searching for extremal (n, d)-trees is also considered for the 2-caterpillars; i.e., the trees in which every vertex lies at distance at most 2 from some simple path. Given n and d ∈ {3, 4}, we completely reveal all extremal 2-caterpillars on n vertices each of which has degree at most d.
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Original Russian Text © D.S. Taletskii, D.S. Malyshev, 2018, published in Diskretnyi Analiz i Issledovanie Operatsii, 2018, Vol. 25, No. 2, pp. 101–123.
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Taletskii, D.S., Malyshev, D.S. On Trees of Bounded Degree with Maximal Number of Greatest Independent Sets. J. Appl. Ind. Math. 12, 369–381 (2018). https://doi.org/10.1134/S1990478918020175
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DOI: https://doi.org/10.1134/S1990478918020175