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A015915
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Numbers n such that sigma(n) + 8 = sigma(n + 8).
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3
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3, 5, 11, 23, 27, 29, 53, 59, 71, 89, 101, 131, 149, 173, 191, 233, 263, 269, 359, 389, 401, 431, 449, 479, 491, 563, 569, 593, 599, 653, 683, 701, 719, 743, 761, 821, 911, 929, 983, 1013, 1031, 1061, 1109, 1163, 1193, 1223, 1229, 1283, 1289
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| Different from A023202. Below 1000000 four composites were found [27, 1615, 1885, 218984] satisfying the "Sigma[x+8]=Sigma[x]+8" relation, together with more than 8000 primes - Labos E. (labos(AT)ana.sote.hu), May 23 2000
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EXAMPLE
| sigma(27)+8=48=sigma(27+8), so 27 is in the sequence.
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MATHEMATICA
| Select[Range[1300], DivisorSigma[1, #]+8==DivisorSigma[1, #+8]&] (* From Harvey P. Dale, Jul 16 2011 *)
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CROSSREFS
| Cf. A015913-A015917, A023200-A023203, A046133, A001359, A054799.
Composite solutions are in A059118.
Sequence in context: A005830 A007008 A018110 * A106901 A154550 A023202
Adjacent sequences: A015912 A015913 A015914 * A015916 A015917 A015918
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KEYWORD
| nonn
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AUTHOR
| Robert G. Wilson v (rgwv(AT)rgwv.com)
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