Semiprimes of form prime - 1.

Terms

a(0) =4a(1) =6a(2) =10a(3) =22a(4) =46a(5) =58a(6) =82a(7) =106a(8) =166a(9) =178a(10) =226a(11) =262a(12) =346a(13) =358a(14) =382a(15) =466a(16) =478a(17) =502a(18) =562a(19) =586a(20) =718a(21) =838a(22) =862a(23) =886a(24) =982a(25) =1018a(26) =1186a(27) =1282a(28) =1306a(29) =1318