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A138309 a(1)=1. a(n) = smallest integer > a(n-1) that is coprime to every (nonzero) exponent in the prime factorization of n. 2
1, 2, 3, 5, 6, 7, 8, 10, 11, 12, 13, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 28, 29, 30, 31, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 46, 47, 48, 49, 51, 53, 54, 55, 57, 59, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 75, 77, 78, 79, 80, 81, 82, 83, 84, 85 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..72.

EXAMPLE

24 has the prime-factorization of 2^3 * 3^1. The smallest integer > a(23)=26 that is coprime to 3 and 1 is 28. (27 is not coprime to 3.) So a(24)=28.

CROSSREFS

Cf. A138308, A138311.

Sequence in context: A183292 A039193 A028798 * A184514 A001068 A039145

Adjacent sequences:  A138306 A138307 A138308 * A138310 A138311 A138312

KEYWORD

nonn

AUTHOR

Leroy Quet, Mar 13 2008

EXTENSIONS

More terms from Sean A. Irvine, Mar 07 2010

STATUS

approved

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Last modified May 23 14:15 EDT 2022. Contains 353975 sequences. (Running on oeis4.)