%I #10 Sep 15 2024 02:39:26
%S 60,84,132,140,156,204,220,228,260,276,308,315,340,348,364,372,380,
%T 444,460,476,492,495,516,532,564,572,580,585,620,636,644,693,708,732,
%U 740,748,765,804,812,819,820,836,852,855,860,868,876,884,940,948,988
%N Numbers of the form p^2 * q * r with primes p < q < r.
%H Amiram Eldar, <a href="/A086975/b086975.txt">Table of n, a(n) for n = 1..10000</a>
%F A001221(a(n)) = 3.
%F A001222(a(n)) = 4.
%F A020639(a(n))^2 divides a(n).
%F A000005(a(n)) = 12. - _Amiram Eldar_, Sep 15 2024
%t Select[Range[1000], FactorInteger[#][[;;, 2]] == {2, 1, 1} &] (* _Amiram Eldar_, Sep 15 2024 *)
%o (PARI) is(k) = factor(k)[, 2] == [2, 1, 1]~; \\ _Amiram Eldar_, Sep 15 2024
%Y Subsequence of A086974 and of A085987.
%Y Cf. A000005, A001221, A001222, A020639.
%K nonn
%O 1,1
%A _Reinhard Zumkeller_, Jul 25 2003