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A015913
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Numbers n such that sigma(n) + 4 = sigma(n + 4).
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18
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3, 7, 13, 19, 37, 43, 67, 79, 97, 103, 109, 127, 163, 193, 223, 229, 277, 307, 313, 349, 379, 397, 439, 457, 463, 487, 499, 613, 643, 673, 739, 757, 769, 823, 853, 859, 877, 883, 907, 937, 967, 1009, 1087, 1093, 1213, 1279, 1297, 1303, 1423
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| This sequence contains the composite number 305635357, so is different from A023200 and A029710 (305635357 is the only composite member of the present sequence below 10^9) - Jud McCranie (JudMcCranie(AT)ugaalum.uga.edu), Jan 07, 2001.
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MATHEMATICA
| Select[Range[1500], DivisorSigma[1, #]+4==DivisorSigma[1, #+4]&] (* From Harvey P. Dale, Nov 04 2011 *)
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CROSSREFS
| Cf. A023200, A029710.
Sequence in context: A106077 A048977 A154650 * A023200 A046136 A098044
Adjacent sequences: A015910 A015911 A015912 * A015914 A015915 A015916
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KEYWORD
| nonn
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AUTHOR
| Robert G. Wilson v (rgwv(AT)rgwv.com)
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