Largest prime <= 2^((n+1)/2).

Terms

a(0) =2a(1) =2a(2) =3a(3) =5a(4) =7a(5) =11a(6) =13a(7) =19a(8) =31a(9) =43a(10) =61a(11) =89a(12) =127a(13) =181a(14) =251a(15) =359a(16) =509a(17) =719a(18) =1021a(19) =1447a(20) =2039a(21) =2887a(22) =4093a(23) =5791a(24) =8191a(25) =11579a(26) =16381a(27) =23167a(28) =32749a(29) =46337