How to lookup a set of dates within a column (filled w/dates) & output values accordingl

Hi there,

This is my first post, so I apologize if I've messed up already! I've been trying to figure out if I should use the IF, OR, VLOOOKUP function for my problem below:

If one date within a set of dates can be found within a column of dates, output this value, otherwise, output a blank field.

=IF(VLOOKUP((OR(B3+7,B3+8,B3+9,B3+10,B3+11,B3+12,B3+13,B3+14)),A:A,1,FALSE),B3+7,"")

So referencing the attached spreadsheet, I'm trying to have the Week Start Date ID output dates on a weekly basis, starting w/date 03/02/2013. I only want 03/09/2013 to be displayed if a date within 03/09/2013 and 03/16/2013 can be found within Column A, 03/17/2013 to be displayed if a date within 03/17/2013 and 03/24/2013 can be found in Column A, and so forth. If it can be found, output the previous week's start date cell + 7, otherwise, output "" (or blank).

I might've not made sense, so feel free to ask questions for further clarification. Thanks so much everyone!!!!!!!!!

Update: sorry, i've updated the thread title as well as the formula used.