Recursion base vs hand-made recursion

[Dan]

Using div_8 and cryptic_function(a) this is the simplified function:

function fss2(seq)
    A = 0; i = 1
    while i <= length(seq)
        if seq[i] == cryptic_function(A)
            A <<= 3; i += 1
        else
            A += 1
            while div_8(A)==0 && A > 0
                A >>= 3; i -= 1
            end
        end
    end
    return A >> 3
end