Product p*q of two primes with q = 2*p + 1.

Terms

a(0) =10a(1) =21a(2) =55a(3) =253a(4) =1081a(5) =1711a(6) =3403a(7) =5671a(8) =13861a(9) =15931a(10) =25651a(11) =34453a(12) =60031a(13) =64261a(14) =73153a(15) =108811a(16) =114481a(17) =126253a(18) =158203a(19) =171991a(20) =258121a(21) =351541a(22) =371953a(23) =392941a(24) =482653a(25) =518671a(26) =703891a(27) =822403a(28) =853471a(29) =869221