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A217740
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Abundant numbers with abundant subscripts.
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1
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60, 84, 90, 104, 132, 160, 176, 186, 208, 228, 240, 260, 282, 304, 308, 336, 342, 354, 368, 378, 400, 416, 426, 438, 450, 464, 474, 498, 522, 546, 570, 576, 594, 618, 642, 654, 666, 696, 720, 728, 740, 762, 786, 804, 812, 820, 834, 852, 860, 882, 900, 910, 918
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OFFSET
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1,1
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COMMENTS
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The abundant-index-of-abundant numbers, or "meta-abundant" numbers.
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LINKS
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EXAMPLE
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The first abundant number is 12, so the first meta-abundant number is the 12th abundant number; A005101(A005101(1))=A005101(12)=60.
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MATHEMATICA
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abQ[n_] := DivisorSigma[1, n] > 2 n; s = {}; c = 0; Do[If[abQ[n], c++; If[abQ[c], AppendTo[s, n]]], {n, 1, 1000}]; s (* Amiram Eldar, Jun 21 2019 *)
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CROSSREFS
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Cf. A006450 (primes with prime subscripts).
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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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