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A349607
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a(n) is the number of divisors of the n-th superabundant number (A004394).
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2
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1, 2, 3, 4, 6, 8, 9, 10, 12, 16, 18, 20, 24, 30, 32, 36, 40, 48, 60, 72, 80, 90, 96, 120, 144, 160, 180, 192, 216, 224, 240, 288, 320, 360, 384, 432, 448, 480, 576, 640, 720, 768, 864, 896, 960, 1152, 1280, 1344, 1440, 1440, 1536, 1728, 1792, 1920, 2304, 2688
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OFFSET
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1,2
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COMMENTS
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First differs from A002183 at n = 20.
The first position n where a(n+1) = a(n) is n = 49: a(49) = a(50) = 1440.
The first position n where a(n+1) < a(n) is n = 173: a(173) = 5308416 and a(174) = 5160960.
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LINKS
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FORMULA
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EXAMPLE
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MATHEMATICA
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s = {}; rm = 0; Do[r = DivisorSigma[1, n]/n; If[r > rm, rm = r; AppendTo[s, DivisorSigma[0, n]]], {n, 1, 10^5}]; s
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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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