Numbers k such that phi(k) + 1 is prime.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =5a(5) =6a(6) =7a(7) =8a(8) =9a(9) =10a(10) =11a(11) =12a(12) =13a(13) =14a(14) =17a(15) =18a(16) =19a(17) =21a(18) =22a(19) =23a(20) =26a(21) =27a(22) =28a(23) =29a(24) =31a(25) =32a(26) =34a(27) =36a(28) =37a(29) =38