Numbers n such that 9^n + 3^(n+1) - 1 is prime.

Terms

a(0) =1a(1) =2a(2) =3a(3) =4a(4) =8a(5) =21a(6) =22a(7) =31a(8) =45a(9) =86a(10) =99a(11) =127a(12) =239a(13) =264a(14) =332a(15) =338a(16) =752a(17) =793a(18) =2310a(19) =4364a(20) =7454a(21) =14788a(22) =20031