Largest prime < e^n.

Terms

a(0) =2a(1) =7a(2) =19a(3) =53a(4) =139a(5) =401a(6) =1093a(7) =2971a(8) =8101a(9) =22013a(10) =59863a(11) =162751a(12) =442399a(13) =1202603a(14) =3269011a(15) =8886109a(16) =24154939a(17) =65659969a(18) =178482289a(19) =485165141a(20) =1318815713a(21) =3584912833a(22) =9744803443a(23) =26489122081a(24) =72004899319a(25) =195729609407a(26) =532048240573