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A341591
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Number of superior prime divisors of n.
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28
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0, 1, 1, 1, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1, 1, 1, 1, 0, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 1, 1, 1, 0, 1, 1, 0, 1, 0, 1, 1, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 0, 0, 1, 1, 1, 1, 1, 0, 1, 0, 1, 1, 0, 1, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 1
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OFFSET
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1
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COMMENTS
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We define a divisor d|n to be superior if d >= n/d. Superior divisors are counted by A038548 and listed by A161908.
All terms are binary numbers.
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LINKS
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EXAMPLE
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The sequence of sets of superior prime divisors of each positive integer begins: {}, {2}, {3}, {2}, {5}, {3}, {7}, {}, {3}, {5}, {11}, {}, {13}, {7}, {5}, {}, {17}, {}, {19}, {5}, ...
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MATHEMATICA
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Table[Length[Select[Divisors[n], PrimeQ[#]&&#>=n/#&]], {n, 100}]
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CROSSREFS
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The strictly inferior version is A333806.
The version for squarefree instead of prime divisors is A341592.
The version for prime power instead of prime divisors is A341593.
Dominates A341642 (the strictly superior version).
The version for odd instead of prime divisors is A341675.
The unique superior prime divisors of the positive positions are A341676.
A033677 selects the smallest superior divisor.
A038548 counts superior (or inferior) divisors.
A056924 counts strictly superior (or strictly inferior) divisors.
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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