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Search: id:A138310
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| A138310 |
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a(1)=1. a(n) = smallest positive integer not occurring among the first n-1 terms of the sequence that is coprime to n and is coprime to every (nonzero) exponent in the prime factorization of n. |
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3
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| 1, 3, 2, 5, 4, 7, 6, 11, 13, 9, 8, 17, 10, 15
(list; graph; listen)
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OFFSET
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1,2
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EXAMPLE
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12 has the prime-factorization of 2^2 * 3^1. The positive integers that don't occur among the first 11 terms of the sequence are 10,12,14,15,16,17,18,19,... Of these integers, 17 is the smallest that is coprime to the exponents in the prime factorization of 12 (ie coprime to 2 and 1) and is coprime to 12. So a(12) = 17.
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CROSSREFS
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Cf. A138308, A138311.
Adjacent sequences: A138307 A138308 A138309 this_sequence A138311 A138312 A138313
Sequence in context: A085229 A093714 A080261 this_sequence A137707 A143527 A095720
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KEYWORD
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more,nonn
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AUTHOR
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Leroy Quet (qq-quet(AT)mindspring.com), Mar 13 2008
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