The function takes a string input and counts the occurrence of unique characters position-wise, ignoring the case.

[CODE]:
def approximate_function(input_string):
    input_string = input_string.lower()
    result = []
    for i, char in enumerate(input_string):
        count = input_string[:i+1].count(char)
        result.append(str(count))
    return " ".join(result)