Products p*q*r*s of distinct primes for which (p*q*r*s - 1)/2 is prime.

Terms

a(0) =1155a(1) =1995a(2) =3135a(3) =3255a(4) =3315a(5) =4935a(6) =5115a(7) =5187a(8) =6783a(9) =7035a(10) =7095a(11) =7215a(12) =7395a(13) =7455a(14) =7755a(15) =8463a(16) =8547a(17) =8715a(18) =9867a(19) =10335a(20) =10455a(21) =10695a(22) =10815a(23) =11055a(24) =11715a(25) =11739a(26) =12243a(27) =12903a(28) =14595a(29) =14835