AR Document sequence-Not able to use existing document sequence name

Hi,

I have already defined a document receivable sequence but noticed that the initial value is not set. Now, I'm unable to edit the existing document sequence to set new Initial value. When I try to create a new document sequence by end-dating the previous one, I cannot use the same name as the one I just end-dated. Is there any way to either change the existing initial value in the document sequence or create a new one with the same name as the end-dated one?