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%I #11 Dec 18 2021 08:07:20
%S 12,18,20,24,28,40,44,45,48,50,52,54,56,63,68,75,76,80,88,92,96,98,99,
%T 104,112,116,117,124,135,136,147,148,152,153,160,162,164,171,172,175,
%U 176,184,188,189,192,207,208,212,224,232,236,242,244,245,248,250,261,268,272,275
%N Numbers with exactly 2 semiprime divisors.
%C Numbers of the form p*q^k, where p and q are distinct primes and k>1.
%H Amiram Eldar, <a href="/A345381/b345381.txt">Table of n, a(n) for n = 1..10000</a>
%e 50 is in the sequence since it has exactly 2 semiprime divisors, 10 and 25.
%t Select[Range[300], Length[(e = Sort[FactorInteger[#][[;; , 2]]])] == 2 && Min[e] == 1 && Max[e] > 1 &] (* _Amiram Eldar_, Sep 30 2021 *)
%o (Python)
%o from sympy import factorint
%o def ok(n):
%o e = sorted(factorint(n).values())
%o return len(e) == 2 and e[0] == 1 and e[1] > 1
%o print([k for k in range(276) if ok(k)]) # _Michael S. Branicky_, Dec 18 2021
%Y Cf. A001358 (semiprimes).
%Y Supersequence of A054753, A096156.
%K nonn
%O 1,1
%A _Wesley Ivan Hurt_, Jun 16 2021
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