Numbers having exactly two distinct prime factors p, q with q = p+2.

Terms

a(0) =15a(1) =35a(2) =45a(3) =75a(4) =135a(5) =143a(6) =175a(7) =225a(8) =245a(9) =323a(10) =375a(11) =405a(12) =675a(13) =875a(14) =899a(15) =1125a(16) =1215a(17) =1225a(18) =1573a(19) =1715a(20) =1763a(21) =1859a(22) =1875a(23) =2025a(24) =3375a(25) =3599a(26) =3645a(27) =4375a(28) =5183a(29) =5491