The smallest prime number greater than 2^n / 3.

Terms

a(0) =2a(1) =2a(2) =3a(3) =7a(4) =11a(5) =23a(6) =43a(7) =89a(8) =173a(9) =347a(10) =683a(11) =1367a(12) =2731a(13) =5471a(14) =10937a(15) =21851a(16) =43691a(17) =87383a(18) =174763a(19) =349529a(20) =699053a(21) =1398107a(22) =2796203a(23) =5592407a(24) =11184829a(25) =22369661a(26) =44739259a(27) =89478503a(28) =178956983a(29) =357913951