%I
%S 9,10,14,15,21,26,33,35,38,39,51,62,65,69,77,86,91,93,95,111,122,123,
%T 129,133,146,159,161,201,203,206,209,213,215,217,218,221,249,278,287,
%U 291,299,301,302,303,305,321,335,339,362,371,381,386,395,398,403,407
%N Numbers n which are a product of two primes j and k such that njk is prime.
%H Harvey P. Dale, <a href="/A088710/b088710.txt">Table of n, a(n) for n = 1..1000</a>
%e a(2)=10 because 10 has only one pair of prime factors (2 and 5) and 1025=3 which is prime.
%t ptpQ[n_]:=PrimeOmega[n]==2&&PrimeQ[nTotal[Flatten[Table[#[[1]],#[[2]]]&/@ FactorInteger[n]]]]; Select[Range[500],ptpQ] (* _Harvey P. Dale_, Jun 04 2018 *)
%Y Cf. A001358.
%K nonn
%O 1,1
%A Chuck Seggelin (barkeep(AT)plastereddragon.com), Oct 11 2003
