Numbers k such that 43^k + 4 is prime.

Terms

a(0) =1a(1) =7a(2) =13a(3) =17a(4) =33a(5) =43a(6) =205a(7) =287a(8) =669a(9) =1161a(10) =1166a(11) =3753a(12) =6095a(13) =18123a(14) =28041