from typing import Sequence


def get_default_topk_args(num_classes: int) -> Sequence[int]:
    """Calculate list params for ``Accuracy@k`` and ``mAP@k``.

    Args:
        num_classes: number of classes

    Returns:
        iterable: array of accuracy arguments

    Examples:
        >>> get_default_topk_args(num_classes=4)
        [1, 3]

        >>> get_default_topk_args(num_classes=8)
        [1, 3, 5]
    """
    result = [1]

    if num_classes is None:
        return result

    if num_classes > 3:
        result.append(3)
    if num_classes > 5:
        result.append(5)

    return result