Least semiprime whose prime factors differ by 2*prime(n).

Terms

a(0) =21a(1) =55a(2) =39a(3) =51a(4) =203a(5) =87a(6) =111a(7) =123a(8) =371a(9) =183a(10) =335a(11) =395a(12) =623a(13) =267a(14) =291a(15) =327a(16) =1703a(17) =635a(18) =411a(19) =1043a(20) =447a(21) =815a(22) =1211a(23) =543a(24) =591a(25) =7223a(26) =1055a(27) =2951a(28) =1115a(29) =687