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Search: id:A140522
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| A140522 |
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Numbers for which sigma(n) - 2n exceeds sigma(k) - 2k for all k < n. |
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+0
1
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| 1, 6, 12, 24, 36, 48, 60, 72, 84, 96, 108, 120, 168, 180, 240, 300, 336, 360, 420, 480, 540, 600, 660, 720, 840, 1008, 1080, 1200, 1260, 1440, 1680, 2100, 2160, 2520, 3240, 3360, 3780, 3960, 4200, 4620, 4680, 5040, 6300, 6720, 7200, 7560, 8400, 9240, 10080
(list; graph; listen)
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OFFSET
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1,2
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EXAMPLE
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72 qualifies because a(60) = 48 and a(72) = 51.
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MATHEMATICA
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a = {1}; m = -1; For[n = 2, n < 20000, n++, If[DivisorSigma[1, n] - 2*n > m, m = DivisorSigma[1, n] - 2*n; AppendTo[a, n]]]; a [From Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Aug 04 2008]
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CROSSREFS
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Cf. A002093 (d=0) and A034090 (d=1).
Adjacent sequences: A140519 A140520 A140521 this_sequence A140523 A140524 A140525
Sequence in context: A110967 A000082 A106697 this_sequence A065218 A124509 A063104
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KEYWORD
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nonn
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AUTHOR
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J. Lowell (jhbubby(AT)mindspring.com), Jul 02 2008
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EXTENSIONS
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More terms from Stefan Steinerberger (stefan.steinerberger(AT)gmail.com), Aug 04 2008
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