Let mindivmathrm{mindiv}mindiv be the minimum divisor greater than 1 of n. Bobo construsts a tree on all positive integer numbers {1,2,…,} by adding edges between n and nmindivfrac{n}{mathrm{mindiv}}mindivn for all n > 1. Let δ(u,v)deltaδ(u,v) be the number of edges between vertices u and v on the tree. Given m and w1,…,wm, Bobo would like to find minu∑i=1mwiδ(u,i!
Let mindiv(n)mathrm{mindiv}(n)mindiv(n) be the minimum divisor greater than 1 of n. Bobo construsts a tree on all positive integer numbers {1,2,…,}{1, 2, dots, }{1,2,…,} by adding edges between n and nmindiv(n)frac{n}{mathrm{mindiv}(n)}mindiv(n)n for all n > 1. Let δ(u,v)delta(u, v)δ(u,v) be the number of edges between vertices u and v on the tree. Given m and w1,…,wmw_1, dots, w_mw1,…,wm, Bobo would like to find minu∑i=1mwiδ(u,i!)min_{u} sum_{i = 1}^{m} w_i delta(u, i!)minu∑i=1mwiδ(u,i!).
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