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A193988
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Numbers n such that sigma2(n) > sigma2(k) for all k < n.
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3
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1, 2, 3, 4, 5, 6, 8, 9, 10, 12, 14, 15, 16, 18, 20, 22, 24, 28, 30, 32, 34, 36, 40, 42, 44, 46, 48, 52, 54, 56, 60, 64, 66, 70, 72, 78, 80, 84, 90, 96, 100, 102, 108, 114, 120, 126, 132, 138, 140, 144, 150, 156, 162, 168, 180, 192, 198, 204, 210, 216, 228
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OFFSET
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1,2
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COMMENTS
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Where record values of sigma2(n) occur. Records transform of A001157.
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LINKS
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T. D. Noe, Table of n, a(n) for n = 1..1000
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MATHEMATICA
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mx = 0; t = {}; Do[u = DivisorSigma[2, n]; If[u > mx, mx = u; AppendTo[t, n]], {n, 1000}]; t
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CROSSREFS
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Cf. A002093 (highly abundant numbers), A193989.
Sequence in context: A225734 A225733 A225732 * A124455 A072378 A112587
Adjacent sequences: A193985 A193986 A193987 * A193989 A193990 A193991
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KEYWORD
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nonn
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AUTHOR
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T. D. Noe, Aug 17 2011
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STATUS
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approved
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