Numbers k such that 9^k + 4 is prime.

Terms

a(0) =0a(1) =1a(2) =3a(3) =5a(4) =11a(5) =15a(6) =21a(7) =87a(8) =99a(9) =281a(10) =497a(11) =2919a(12) =6849a(13) =7365a(14) =8483a(15) =49317a(16) =58611