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A193988
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Numbers n such that sigma_2(n) > sigma_2(k) for all k < n.
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4
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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 sigma_2(n) occur. Records transform of A001157.
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LINKS
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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
DeleteDuplicates[Table[{n, DivisorSigma[2, n]}, {n, 1000}], GreaterEqual[#1[[2]], #2[[2]]]&][[All, 1]] (* Harvey P. Dale, May 14 2022 *)
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CROSSREFS
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KEYWORD
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nonn
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AUTHOR
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STATUS
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approved
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