Sequence of semiprimes with all cumulating sums being semiprime.

Terms

a(0) =4a(1) =6a(2) =15a(3) =26a(4) =55a(5) =111a(6) =237a(7) =469a(8) =926a(9) =1858a(10) =3711a(11) =7419a(12) =14849a(13) =29693a(14) =59435a(15) =118821a(16) =237722a(17) =475378a(18) =950738a(19) =1901474a(20) =3802967a(21) =7605921a(22) =15211942a(23) =30423869a(24) =60847667a(25) =121695326a(26) =243390743a(27) =486781401a(28) =973562795a(29) =1947125641