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A066971
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a(n) = sigma(sigma(sigma(n))).
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7
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1, 7, 8, 15, 28, 56, 24, 60, 24, 56, 56, 120, 60, 168, 168, 63, 56, 120, 96, 252, 104, 112, 168, 480, 63, 252, 234, 360, 195, 336, 104, 210, 224, 360, 224, 248, 168, 480, 360, 546, 252, 728, 224, 504, 480, 336, 224, 504, 186, 255, 336, 260, 360, 1170, 336, 1170
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OFFSET
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1,2
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COMMENTS
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LINKS
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MATHEMATICA
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Table[Nest[DivisorSigma[1, #]&, n, 3], {n, 60}] (* Harvey P. Dale, Apr 06 2023 *)
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PROG
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(PARI) for(n=1, 100, print1(sigma(sigma(sigma(n))), ", ")) \\ Lambert Klasen
(PARI) { for (n=1, 1000, write("b066971.txt", n, " ", sigma(sigma(sigma(n)))) ) } \\ Harry J. Smith, Apr 12 2010
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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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