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%I #11 Apr 06 2021 04:42:39
%S 1,4,9,14,18,21,25,26,33,38,42,46,49,50,57,62,69,74,78,85,92,93,94,
%T 106,110,121,129,130,133,134,138,140,145,154,164,166,169,177,178,189,
%U 204,205,213,217,218,222,225,226,230,236,237,249,253,254,262,265,266,278
%N Numbers n such that sopfr(Omega(n)) = Omega(sopfr(n)), where Omega(m) is the number and sopfr(m) is the sum of prime factors of m, with repetition respectively.
%C A001414(A001222(a(n))) = A001222(A001414(a(n)));
%C squares of primes (A001248) are a subsequence.
%e n=189=3*3*3*7: Omega(sopfr(189)=Omega(3+3+3+7)=Omega(16)=4, sopfr(Omega(189))=sopfr(4)=2+2=4, therefore 189 is a term.
%t sopfr[n_] := If[n == 1, 0, Total[Times @@@ FactorInteger[n]]];
%t Select[Range[1000], If[# == 1, True, sopfr[PrimeOmega[#]] == PrimeOmega[sopfr[#]]]&] (* _Jean-François Alcover_, Apr 06 2021 *)
%Y Cf. A001222, A001414, A001248, A076361.
%K nonn
%O 1,2
%A _Reinhard Zumkeller_, Mar 04 2003
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