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A335052
Odd unitary abundant numbers whose unitary abundancy is closer to 2 than that of any smaller odd unitary abundant number.
3
15015, 19635, 21945, 23205, 25935, 31395, 33915, 39585, 41055, 45885, 51765, 80535, 83265, 354585, 359205, 361515, 366135, 382305, 389235, 400785, 403095, 407715, 414645, 416955, 423885, 430815, 437745, 442365, 77967015, 132335385, 617102535, 724239285, 1756753845
OFFSET
1,1
COMMENTS
The unitary abundancy of a number k is usigma(k)/k, where usigma(k) is the sum of unitary divisors of k (A034448).
EXAMPLE
The unitary abundancies of the first terms are 2.148..., 2.112..., 2.099..., 2.085..., 2.072..., ...
MATHEMATICA
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
CROSSREFS
KEYWORD
nonn
AUTHOR
Amiram Eldar, May 21 2020
STATUS
approved