a(n) = period length of the sequence A020639(n^k - 1), k >= 1.

Terms

a(0) =1a(1) =1a(2) =1a(3) =1a(4) =1a(5) =2a(6) =1a(7) =1a(8) =1a(9) =12a(10) =1a(11) =10a(12) =1a(13) =1a(14) =1a(15) =60a(16) =1a(17) =10a(18) =1a(19) =1a(20) =1a(21) =18a(22) =1a(23) =2a(24) =1a(25) =1a(26) =1a(27) =660a(28) =1a(29) =66