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A212641
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Largest odd divisor of A212640(n) (number of divisors of n-th powerful number that is the first integer of its prime signature).
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2
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1, 3, 1, 5, 3, 9, 7, 3, 1, 15, 1, 9, 9, 5, 5, 21, 3, 27, 11, 3, 25, 7, 9, 3, 27, 15, 1, 45, 13, 15, 35, 3, 9, 27, 9, 7, 33, 5, 15, 5, 63, 21, 15, 9, 45, 9, 1, 11, 9, 3, 75, 1, 39, 25, 21, 81, 49, 5, 3, 81, 27, 45, 17, 21, 55, 3, 27, 7, 3, 13, 45, 15, 105, 9, 45
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OFFSET
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1,2
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COMMENTS
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The odd part of d(n), or largest odd divisor of d(n) (A212181(n)), is a function of the second signature of n (cf. A212172). Since A181800 gives the first integer of each second signature, this sequence gives the value of A212181 for each second signature in order of its first appearance.
Note: The odd part of d(n) is not the same as the number of odd divisors of n (A001227(n)).
Each odd integer appears an infinite number of times.
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LINKS
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FORMULA
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EXAMPLE
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A181800(5) = 32 has 6 divisors (1, 2, 4, 8, 16 and 32). The largest odd divisor of 6 is 3. Hence, a(5) = 3.
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CROSSREFS
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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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