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1, 5, 6, 7, 11, 13, 17, 19, 23, 29, 30, 31, 35, 37, 41, 42, 43, 47, 53, 55, 59, 61, 65, 66, 67, 71, 72, 73, 77, 78, 79, 83, 85, 89, 91, 95, 97, 101, 102, 103, 107, 108, 109, 113, 114, 115, 119, 127, 131, 133, 137, 138, 139, 143, 145, 149, 151, 155, 157, 161
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OFFSET
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1,2
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COMMENTS
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For any n > 0, A279510(A279510(n)) belongs to this sequence (and this sequence is infinite).
For any n > 0:
- a(n) is a multiple of 2 iff a(n) is a multiple of 3,
- if a prime p > 3 divides a(n), then the p-adic valuation of a(n) belongs to this sequence.
Squarefree numbers coprime to 6 are in this sequence, and all members of this sequence are 0, 1, or 5 mod 6, so the lower density is at least 3/Pi^2 = 0.303... and the upper density is at most 1/2. This could be improved with more care. - Charles R Greathouse IV, May 17 2024
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LINKS
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EXAMPLE
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A300955(42) = 42 hence 42 belongs to this sequence.
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MAPLE
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b:= n-> `if`(n=1, 1, mul(`if`(i[1]=2, 3, `if`(i[1]=3,
2, i[1]))^b(i[2]), i=ifactors(n)[2])):
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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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