#!/usr/bin/python
"OEIS A181391, Van Eck's sequence. <https://oeis.org/A181391>"

vaneck = [0]
while True:
    print vaneck[-1]
    if vaneck[-1] not in vaneck[:-1]:
        vaneck.append(0)
    else:
        i = start = len(vaneck) - 2
        while vaneck[i] != vaneck[-1]:
            i -= 1
        vaneck.append(start - i + 1)