Primes of the form q*2^h - 1, where q is a Fermat prime.

Terms

a(0) =2a(1) =5a(2) =11a(3) =19a(4) =23a(5) =47a(6) =67a(7) =79a(8) =191a(9) =271a(10) =383a(11) =1087a(12) =1279a(13) =4111a(14) =5119a(15) =6143a(16) =16447a(17) =20479a(18) =81919a(19) =262147a(20) =263167a(21) =786431a(22) =1114111a(23) =1310719a(24) =16842751a(25) =17825791a(26) =1073758207a(27) =4295032831a(28) =4311744511a(29) =17180131327