Semiprimes p such that next semiprime after p is p+20.

Terms

a(0) =2681a(1) =3523a(2) =6953a(3) =8227a(4) =16817a(5) =26101a(6) =28533a(7) =28563a(8) =28617a(9) =29011a(10) =34249a(11) =37007a(12) =42401a(13) =49983a(14) =50117a(15) =55703a(16) =60657a(17) =65083a(18) =66938a(19) =71381a(20) =71873a(21) =73443a(22) =76247a(23) =92773a(24) =92978a(25) =101109a(26) =101271a(27) =109129a(28) =111479a(29) =112051