Semiprimes in A103372.

Terms

a(0) =4a(1) =9a(2) =15a(3) =21a(4) =33a(5) =38a(6) =58a(7) =86a(8) =106a(9) =122a(10) =485a(11) =905a(12) =1939a(13) =4163a(14) =6697a(15) =12381a(16) =14473a(17) =22889a(18) =107833a(19) =170769a(20) =370729a(21) =687634a(22) =804106a(23) =1093762a(24) =1276259a(25) =2767999a(26) =11140379a(27) =15186449a(28) =210634829a(29) =286937249