Periods of sum of 10th powers of digits iterated until the sequence becomes periodic.

Terms

a(0) =1a(1) =1a(2) =17a(3) =123a(4) =17a(5) =17a(6) =123a(7) =123a(8) =123a(9) =123a(10) =1a(11) =17a(12) =123a(13) =17a(14) =123a(15) =123a(16) =123a(17) =81a(18) =81a(19) =123a(20) =17a(21) =123a(22) =123a(23) =123a(24) =123a(25) =123a(26) =123a(27) =123a(28) =123a(29) =123