A025521 Least k>1 such that complement of first n terms of A022303 repeats beginning at k-th term.

2, 2, 2, 15, 15, 15, 15, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 41, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 123, 691, 691, 691, 691, 691, 691, 691, 691, 691, 691, 691, 691, 691, 691, 691, 691, 691, 691, 691, 691, 691