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A328457
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Length of the longest run of divisors > 1 of n.
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10
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0, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 3, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 3, 1, 1, 1, 2, 1, 2, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 5, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 3, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 3, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 3, 1, 1, 1, 2, 1, 2, 1, 1, 1
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OFFSET
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1,6
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LINKS
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MATHEMATICA
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Table[If[n==1, 0, Max@@Length/@Split[Rest[Divisors[n]], #2==#1+1&]], {n, 100}]
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PROG
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(PARI) A328457(n) = { my(rl=0, pd=0, m=0); fordiv(n, d, if(d>1, if(d>(1+pd), m = max(m, rl); rl=0); pd=d; rl++)); max(m, rl); }; \\ Antti Karttunen, Feb 23 2023
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CROSSREFS
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Positions of 0's and 1's are A088725.
The version that looks at all divisors (including 1) is A055874.
The number of successive pairs of divisors > 1 of n is A088722(n).
The Heinz number of the multiset of run-lengths of divisors of n is A328166(n).
The longest run of nontrivial divisors of n is A328458(n).
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KEYWORD
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nonn
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AUTHOR
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EXTENSIONS
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STATUS
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approved
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