def generate_sequence(lst: list[int]) -> list[int]:
    """Return a new list that contains the sequence of integers between the minimum and maximum of
    lst, inclusive.

    When the minimum and maximum of lst are the same, the list should only contain one element.

    Assume that len(lst) >= 1.

    >>> generate_sequence([2])
    [2]
    >>> generate_sequence([15, 19, 18])
    [15, 16, 17, 18, 19]
    """
    return list(range(min(lst), max(lst) + 1))