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%I #11 Apr 14 2023 03:47:41
%S 24,48,56,112,192,248,252,328,448,496,768,1016,1792,1984,2032,3240,
%T 6462,7936,8128,11616,11808,17412,20538,32512,49152,65528,114688,
%U 131056,507904,524224,786432,1048568,1835008,2080768,2096896,2097136,3145728,4194296,7340032
%N Nonunitary superperfect numbers: numbers k such that nusigma(nusigma(k)) = k, where nusigma(k) = sigma(k) - usigma(k) is the sum of nonunitary divisors of k (A048146).
%C Analogous to superperfect numbers (A019279) as nonunitary perfect numbers (A064591) is analogous to perfect numbers (A000396).
%H Amiram Eldar, <a href="/A329884/b329884.txt">Table of n, a(n) for n = 1..53</a> (terms below 10^10)
%t usigma[1] = 1; usigma[n_] := Times @@ (1 + Power @@@ FactorInteger[n]); nusigma[n_] := DivisorSigma[1, n] - usigma[n]; Select[Range[10^6], nusigma[nusigma[#]] == # &]
%Y Cf. A000396, A019279, A034448, A038843, A048146, A064591, A329881.
%K nonn
%O 1,1
%A _Amiram Eldar_, Nov 23 2019