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Numbers k such that sopfr(k) = ud(k), where sopfr = A001414 and ud = A034444.
1

%I #14 Apr 02 2020 07:48:46

%S 2,5460,9240,253890,358050,387090,395850,429660,440895,458850,468930,

%T 475020,529074,550620,574770,629850,669900,755820,788970,803880,

%U 821100,828828,895356,896610,948090,985320,986700,1065900,1123122,1168860,1184040,1279080,1331330

%N Numbers k such that sopfr(k) = ud(k), where sopfr = A001414 and ud = A034444.

%H Amiram Eldar, <a href="/A064029/b064029.txt">Table of n, a(n) for n = 1..3000</a>

%t Select[Range[10^6], Plus @@ Times @@@(f = FactorInteger[#]) == 2^Length@f &] (* _Amiram Eldar_, Dec 01 2019 *)

%o (PARI) sopfr(n, s, fac, i) = fac=factor(n); for(i=1,matsize(fac)[1], s=s+fac[i,1]*fac[i,2]); return(s);

%o isok(k) = sopfr(k) == 2^omega(k);

%Y Cf. A001414, A034444.

%K nonn

%O 1,1

%A _Jason Earls_, Sep 12 2001