A031213 Periods of sum of 10th powers of digits iterated until the sequence becomes periodic.

1, 17, 123, 17, 17, 123, 123, 123, 123, 1, 17, 123, 17, 123, 123, 123, 81, 81, 123, 17, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 17, 123, 123, 123, 123, 123, 81, 17, 123, 17, 123, 123, 123, 123, 123, 7, 123, 123, 123, 17, 123, 123, 123, 123