Table T(n,k) in which n-th row lists prime factors of 2^n - 1 (n >= 2), without repetition.

Terms

a(0) =0a(1) =1a(2) =3a(3) =7a(4) =3a(5) =5a(6) =31a(7) =3a(8) =7a(9) =127a(10) =3a(11) =5a(12) =17a(13) =7a(14) =73a(15) =3a(16) =11a(17) =31a(18) =23a(19) =89a(20) =3a(21) =5a(22) =7a(23) =13a(24) =8191a(25) =3a(26) =43a(27) =127a(28) =7a(29) =31