Compile values from columns on different sheets to column on summary sheet without duplicates.

[BigMoe]

I have a workbook that tracks stock transactions. There are 53 sheets in the workbook labeled "1" through "53", each one being one week of transactions and each sheet is identical. I have one additional summary sheet that compiles the weekly data into yearly stats. I would like to take the stock symbols listed in column K of each weekly sheet and compile them in column B of the summary sheet without any duplicates. After each market close, the weekly sheets get updated manually, so column B on the summary sheet would need to automatically update with the new data entered.

The difficulty I am having is that the symbols are never the same week to week, I never know ahead of time what symbols are traded, and there are way too many available symbols to make a predefined list on the summary sheet.

Since I'm not very familiar with macros, I'd like to stay in the formula world if possible.

Any help, suggestions, or pointing in the right direction would be much appreciated.