A026409 For n >= 1, n n's take places at stage n: the first takes the least untaken place (l.u.p) and for 2<=k<=n, the k-th n takes the l.u.p. more than n-1 places past the place of the (k-1)st n.

1, 2, 3, 2, 4, 3, 5, 6, 3, 4, 7, 5, 8, 4, 6, 9, 5, 4, 7, 10, 6, 5, 8, 11, 9, 7, 5, 6, 12, 10, 8, 13, 7, 6, 9, 11, 14, 15, 8, 6, 7, 10, 12, 9, 13, 16, 8, 7, 11, 17, 14, 10, 9, 15, 7, 8, 12, 13, 18, 11, 19, 9, 10, 8, 14, 16, 17, 20, 12, 15, 9, 8, 10, 11, 13