Least number m such that 9^m == +- 1 (mod 9n + 1).

Terms

a(0) =1a(1) =9a(2) =3a(3) =9a(4) =11a(5) =10a(6) =8a(7) =3a(8) =2a(9) =3a(10) =10a(11) =27a(12) =29a(13) =63a(14) =8a(15) =7a(16) =15a(17) =81a(18) =21a(19) =45a(20) =18a(21) =99a(22) =6a(23) =15a(24) =28a(25) =46a(26) =5a(27) =55a(28) =65a(29) =15