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A075824
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Odd numbers that cannot be expressed as 2^n-3^m where n and m are integers.
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2
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9, 11, 17, 19, 21, 25, 27, 33, 35, 39, 41, 43, 45, 49, 51, 53, 57, 59, 65, 67, 69, 71, 73, 75, 77, 79, 81, 83, 85, 87, 89, 91, 93, 95, 97, 99, 103, 105, 107, 109, 111, 113, 115, 117, 121, 123, 129, 131, 133, 135, 137, 139, 141, 143, 145, 147, 149, 151, 153, 155, 157
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| All listed terms can be certified by considering 2^n-3^m modulo 2552550. [From Max Alekseyev (maxale(AT)gmail.com), Feb 08 2010]
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REFERENCES
| R. K. Guy, Unsolved Problems in Number Theory, D9.
T. N. Shorey and R. Tijdeman, Exponential Diophantine Equations, Cambridge University Press, 1986.
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LINKS
| T. Metsankyla, Catalan's Conjecture : Another old Diophantine problem solved
Wikipedia, Catalan's conjecture
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EXAMPLE
| 5 doesn't belong to the sequence because it can be expressed as 2^3-3^1
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CROSSREFS
| Complement of A192110 in the odd integers.
Cf. A074981.
Sequence in context: A027694 A063191 A048464 * A108113 A111391 A077788
Adjacent sequences: A075821 A075822 A075823 * A075825 A075826 A075827
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KEYWORD
| nonn
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AUTHOR
| Felice Russo (frusso(AT)micron.com), Oct 14 2002
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EXTENSIONS
| Inserted "odd" in definition. - N. J. A. Sloane (njas(AT)research.att.com), Jan 30 2009
Jon Schoenfield observed that 49 was missing, Jan 30 2009
More terms from Max Alekseyev (maxale(AT)gmail.com), Feb 08 2010
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