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A356573
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Sigma-dense numbers: integers k such that sigma(k) * log(1+log(1+log(1+k))) / (k * log(1+log(1+k))) sets a new record.
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0
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1, 2, 4, 6, 12, 24, 60, 120, 240, 360, 720, 840, 1260, 1680, 2520, 5040, 10080, 15120, 27720, 55440, 110880, 166320, 277200, 332640, 554400, 720720, 1441440, 2162160, 3603600, 4324320, 7207200, 10810800, 21621600, 36756720, 61261200, 73513440, 122522400, 183783600
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OFFSET
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1,2
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COMMENTS
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This sequence is to A210594 (the generalization in the latter's comment section) as sigma (A000203, the sum of divisors function) is to tau (A000005, the number of divisors function).
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LINKS
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MATHEMATICA
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s={}; dm = 0; Do[If[(d = DivisorSigma[1, n] * Log[1 + Log[1 + Log[1 + n]]] / (n * Log[1 + Log[1 + n]])) > dm, dm = d; AppendTo[s, n]], {n, 1, 10^5}]; s (* Amiram Eldar, Dec 12 2022 *)
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PROG
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(PARI) listas(nn) = {my(m=0); for (k=1, nn, my(mm = sigma(k)*log(1+log(1+log(1+k))) / (k * log(1+log(1+k)))); if (mm > m, print1(k, ", "); m = mm); ); } \\ Michel Marcus, Dec 12 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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EXTENSIONS
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STATUS
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approved
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