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Search: id:A110108
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| A110108 |
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Conjectured values of n such that sigma(n)+sigma(k)=sigma(n+k) has no solution. |
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+0
2
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| 3, 9, 15, 21, 27, 39, 57, 63, 81, 93, 105, 117, 165, 171, 183, 189, 201, 219, 225, 243, 256, 279, 303, 309, 333, 351, 363, 375, 381, 387, 405, 417, 441, 453, 465, 471, 489, 512, 543, 549, 567, 579, 603, 633, 651, 657, 669, 687, 693, 711, 723, 729, 741, 777
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OFFSET
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1,1
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COMMENT
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All k<10^10 have been checked. Note that this sequence appears to contain all powers of 3. It also contains 256 and 512, which are the only even numbers listed here.
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REFERENCES
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R. K. Guy, Unsolved Problems in Number Theory, 3rd Ed., New York, Springer-Verlag, 2004, Section B15.
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CROSSREFS
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Cf. A066435 (least k such that sigma(n)+sigma(k)=sigma(n+k)).
Sequence in context: A030594 A032676 A016945 this_sequence A162843 A102954 A162486
Adjacent sequences: A110105 A110106 A110107 this_sequence A110109 A110110 A110111
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KEYWORD
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nonn
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AUTHOR
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T. D. Noe (noe(AT)sspectra.com), Jul 12 2005
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