Numbers k such that A007408(k) is prime.

Terms

a(0) =3a(1) =15a(2) =19a(3) =26a(4) =31a(5) =129a(6) =139a(7) =211a(8) =242a(9) =246a(10) =251a(11) =474a(12) =552a(13) =558a(14) =694a(15) =801a(16) =1001a(17) =1123a(18) =1313a(19) =1687a(20) =4168a(21) =4484a(22) =5611a(23) =6869a(24) =12197a(25) =13472