"""
Hi,
Very cool article.
Its important to note that you have 101 terms there:
[0, 0, 1, 0, 2, 0, 2, 2, 1, 6, 0, 5, 0, 2, 6, 5, 4, 0, 5, 3, 0, 3, 2, 9, 0, 4, 9, 3, 6, 14, 0, 6, 3, 5, 15, 0, 5, 3, 5, 2, 17, 0, 6, 11, 0, 3, 8, 0, 3, 3, 1, 42, 0, 5, 15, 20, 0, 4, 32, 0, 3, 11, 18, 0, 4, 7, 0, 3, 7, 3, 2, 31, 0, 6, 31, 3, 6, 3, 2, 8, 33, 0, 9, 56, 0, 3, 8, 7, 19, 0, 5, 37, 0, 3, 8, 8, 1, 46, 0, 6, 23]

The provided code is indented incorrectly and uses and obscure python feature of a for else.
Here is the "correct" code:
"""
def example(terms: int):
    A181391 = [0, 0]
    for n in range(1, terms):
        for m in range(n-1, -1, -1):
            if A181391[m] == A181391[n]:
                A181391.append(n-m)
                break
        else:
            A181391.append(0)
    return A181391


# also here is some "easier" to understand code:
def van_eck(n: int) -> list[int]:
    if n < 1:
        return []
    seq = [0]
    seen = {}
    for i in range(n - 1):
        cur = seq[i]
        if cur in seen:
            next = i - seen[cur]
            seen[cur] = i
            seq.append(next)
        else:
            seq.append(0)
            seen[cur] = i

    return seq

# Thank you for the article