Least number k > 0 such that ((2n-1)^k + 1)/(2n) is prime, or 0 if no such prime exists.

Terms

a(0) =3a(1) =5a(2) =3a(3) =3a(4) =5a(5) =3a(6) =3a(7) =7a(8) =17a(9) =3a(10) =11a(11) =3a(12) =0a(13) =7a(14) =109a(15) =5a(16) =11a(17) =5a(18) =3a(19) =17a(20) =5a(21) =103a(22) =5a(23) =7a(24) =3a(25) =21943a(26) =3a(27) =53a(28) =17a(29) =7