a(n) is the smallest prime factor of n*2^n-1.

Terms

a(0) =7a(1) =23a(2) =3a(3) =3a(4) =383a(5) =5a(6) =23a(7) =17a(8) =3a(9) =3a(10) =23a(11) =5a(12) =5a(13) =7a(14) =3a(15) =3a(16) =79a(17) =13a(18) =1879a(19) =13a(20) =3a(21) =3a(22) =47a(23) =7a(24) =229a(25) =5a(26) =3a(27) =3a(28) =32212254719a(29) =263