Semiprimes in A103377.

Terms

a(0) =4a(1) =9a(2) =15a(3) =21a(4) =33a(5) =38a(6) =58a(7) =65a(8) =86a(9) =106a(10) =121a(11) =129a(12) =265a(13) =511a(14) =8114a(15) =8193a(16) =16307a(17) =16853a(18) =17855a(19) =19857a(20) =31298a(21) =68037a(22) =104739a(23) =124205a(24) =131209a(25) =134149a(26) =140457a(27) =152849a(28) =252914a(29) =259918