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Odd unitary abundant numbers whose unitary abundancy is closer to 2 than that of any smaller odd unitary abundant number.
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%I #7 May 21 2020 21:19:58

%S 15015,19635,21945,23205,25935,31395,33915,39585,41055,45885,51765,

%T 80535,83265,354585,359205,361515,366135,382305,389235,400785,403095,

%U 407715,414645,416955,423885,430815,437745,442365,77967015,132335385,617102535,724239285,1756753845

%N Odd unitary abundant numbers whose unitary abundancy is closer to 2 than that of any smaller odd unitary abundant number.

%C The unitary abundancy of a number k is usigma(k)/k, where usigma(k) is the sum of unitary divisors of k (A034448).

%e The unitary abundancies of the first terms are 2.148..., 2.112..., 2.099..., 2.085..., 2.072..., ...

%t usigma[1] = 1; usigma[n_] := Times @@ (1 + Power @@@ FactorInteger[n]); seq = {}; r = 3; Do[s = usigma[n]/n; If[s > 2 && s < r, AppendTo[seq, n]; r = s], {n, 1, 10^6, 2}]; seq

%Y Cf. A034448, A129485, A188263, A302570, A335053, A335055.

%K nonn

%O 1,1

%A _Amiram Eldar_, May 21 2020