Prime closest to e^n.

Terms

a(0) =2a(1) =3a(2) =7a(3) =19a(4) =53a(5) =149a(6) =401a(7) =1097a(8) =2971a(9) =8101a(10) =22027a(11) =59879a(12) =162751a(13) =442399a(14) =1202603a(15) =3269011a(16) =8886109a(17) =24154957a(18) =65659969a(19) =178482289a(20) =485165237a(21) =1318815713a(22) =3584912833a(23) =9744803443a(24) =26489122147a(25) =72004899319