Primes that remain prime through 4 iterations of function f(x) = 2x + 9.

Terms

a(0) =11a(1) =31a(2) =1181a(3) =2521a(4) =3701a(5) =4211a(6) =4931a(7) =8221a(8) =8461a(9) =9871a(10) =11981a(11) =13121a(12) =14591a(13) =16381a(14) =16901a(15) =21991a(16) =23021a(17) =34961a(18) =36781a(19) =37691a(20) =43991a(21) =44531a(22) =45181a(23) =46021a(24) =46051a(25) =52321a(26) =57601a(27) =59921a(28) =62081a(29) =75391