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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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2
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1, 3, 2, 5, 4, 7, 6, 11, 13, 9, 8, 17, 10, 15, 14, 19, 12, 23, 16, 21, 20, 25, 18, 29, 27, 31, 22, 33, 24, 37, 26, 39, 28, 35, 32, 41, 30, 43, 34, 47, 36, 53, 38, 45, 49, 51, 40, 55, 57, 59, 44, 61, 42, 65, 46, 67, 50, 63, 48, 71, 52, 69, 73, 77, 54, 79, 56, 75, 58, 81, 60, 83
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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EXAMPLE
| 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
| Cf. A138308, A138311.
Sequence in context: A085229 A093714 A080261 * A191709 A194077 A137707
Adjacent sequences: A138307 A138308 A138309 * A138311 A138312 A138313
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KEYWORD
| nonn
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AUTHOR
| Leroy Quet Mar 13 2008
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EXTENSIONS
| More terms from Max Alekseyev (maxale(AT)gmail.com), Apr 24 2010
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