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A280801
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Least k > 0 such that (2*n)^k is in A002202, or 0 if no such k exists.
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1
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1, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 2, 1, 1, 1, 4, 1, 3, 1, 1, 1, 1, 1, 2, 1, 1, 1, 1, 1, 5, 1, 1, 2, 1, 1, 2, 3, 1, 1, 1, 1, 15, 1, 2, 1, 2, 1, 3, 1, 1, 1, 1, 1, 1, 1, 2, 1, 3, 1, 7, 2, 1, 1, 1, 1, 2, 1, 1, 1, 3, 1, 2, 1, 1, 3, 3, 1, 8, 1, 1, 1, 1, 1, 2, 1, 2, 1, 1, 1, 4, 1, 2, 2, 1, 1, 4, 1, 1, 1, 17, 1, 2, 1, 1, 1, 3, 1, 3, 1, 1, 1, 1, 1, 2, 1, 2, 2, 1, 1, 2, 5, 2, 2, 1, 1, 4, 1, 3
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OFFSET
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1,7
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COMMENTS
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Least k such that A280801(k) = n, or 0 if no such k exists are 1, 7, 19, 17, 31, 223, 61, 79, 151, 383, 181, 347, 523, 1109, 43, 607, 101, 733, 1033, 409, 1783, 1123, 199, 1471, 1301, 5113, 1801, 2311, 3617, 1699, 1543, 7489, 2663, 4583, 7829, 2749, 4177, 5179, 2389, 13291, 20389, ...
What is the asymptotic behavior of this sequence?
Conjecture: a(n) > 0 for all values of n. - Altug Alkan, Jan 11 2017
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LINKS
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FORMULA
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EXAMPLE
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a(43) = 15 because (43*2)^k is not in A002202 for 0 < k < 15 and 86^15 = 104106241746467411129608011776 is in A002202.
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PROG
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(PARI) a(n) = {my(k = 1); while (!istotient((2*n)^k), k++); k; }
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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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