Smallest twin prime > 2^n.

Terms

a(0) =3a(1) =5a(2) =11a(3) =17a(4) =41a(5) =71a(6) =137a(7) =269a(8) =521a(9) =1031a(10) =2081a(11) =4127a(12) =8219a(13) =16451a(14) =32801a(15) =65537a(16) =131111a(17) =262151a(18) =524351a(19) =1048889a(20) =2097257a(21) =4194581a(22) =8388617a(23) =16777289a(24) =33554501a(25) =67109321a(26) =134217779a(27) =268435577a(28) =536871017a(29) =1073741831