Multiplicative digital root of n (keep multiplying digits of n until reaching a single digit).

Terms

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