What you are fatally missing is a method to compute X. For instance, what happens when I measure the information of 2*N? Is that 2*X?
I can make an educated guess based upon your description. If you have a sequence A of length N that has information value X and you change it like you describe you will eventually end up with a sequence B of length N that has information value X. Based upon that, the only dependency you have put upon the value of information is the length of the sequence.
So if I duplicate sequence A and point mutate sequence A into sequence B I will have 2X information. Sequence B is free to mutate because sequence A, and therefore its function, is unchanged to no detrement of the whole.
Being that this does actually happen in real life, information is therefore shown to increase.
Of course, biblical creationists are committed to belief in God's written Word, the Bible, which forbids bearing false witness; --AIG (lest they forget)