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 A234520 Composite numbers n sorted by decreasing values of beta(n) = sigma(n)^(1/n) - (n+1)^(1/n), where sigma(n) = A000203(n) = the sum of divisors of n. 12
 4, 6, 8, 12, 10, 18, 16, 24, 14, 20, 9, 15, 30, 36, 28, 22, 32, 40, 48, 42, 21, 26, 60, 54, 44, 27, 72, 56, 34, 50, 45, 52, 38, 66, 84, 33, 64, 90, 80, 70, 96, 78, 46, 39, 120, 68, 108, 35, 88, 76, 63, 25, 100, 58, 102, 126, 144, 112, 132, 62, 104, 75, 51, 92 (list; graph; refs; listen; history; text; internal format)
 OFFSET 1,1 COMMENTS The number beta(n)  = sigma(n)^(1/n) - (n+1)^(1/n) is called the beta-deviation from primality of the number n; beta(p) = 0 for p = prime. See A234516 for definition of alpha(n). For number 4; beta(4) = sigma(4)^(1/4) - (4+1)^(1/4), = 7^(1/4) - 5^(1/4) = 0,131227780… = A234522 (maximal value of function beta(n)). Lim_n->infinity beta(n) = 0. Conjecture: Every composite number n has a unique value of number beta(n). See A234523 - sequence of numbers a(n) such that a(n) > a(k) for all k < n. LINKS Jaroslav Krizek, Table of n, a(n) for n = 1..1000 CROSSREFS Cf. A234515, A234516, A234517, A234518, A234519, A234521, A234522, A234523, A234524. Sequence in context: A320127 A110646 A320126 * A275789 A031359 A274790 Adjacent sequences:  A234517 A234518 A234519 * A234521 A234522 A234523 KEYWORD nonn AUTHOR Jaroslav Krizek, Jan 14 2014 STATUS approved

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Last modified December 10 15:09 EST 2019. Contains 329896 sequences. (Running on oeis4.)