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A072087
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Least k such that A072084(k) = n.
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1
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1, 3, 7, 9, 31, 21, 127, 27, 49, 93, 3583, 63, 8191, 381, 217, 81, 131071, 147, 524287, 279, 889, 10749, 14680063, 189, 961, 24573, 343, 1143, 1073479679, 651, 2147483647, 243, 25081, 393213, 3937, 441, 266287972351, 1572861, 57337, 837
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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COMMENTS
| If p is a Mersenne-prime then a(p) = 2^p - 1 (A000120(2^n-1)=n), for other primes p: a(p) > 2^p - 1.
This sequence may be multiplicative. - Mitch Harris, Apr 19 2005
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FORMULA
| Completely multiplicative with a(p) = A061712(p). - David W. Wilson (davidwwilson(AT)comcast.net), Aug 03 2005
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CROSSREFS
| Cf. A000120, A000043.
Sequence in context: A033958 A018827 A057840 * A031161 A031882 A199190
Adjacent sequences: A072084 A072085 A072086 * A072088 A072089 A072090
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KEYWORD
| nonn,mult
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AUTHOR
| Reinhard Zumkeller (reinhard.zumkeller(AT)gmail.com), Jun 14 2002
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EXTENSIONS
| More terms from David W. Wilson (davidwwilson(AT)comcast.net), Aug 03 2005
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