[math-fun] Domino problem

I thank Richard Guy for his answer (negative) to the converse domino question I posed. Can someone please tell me where to find the "Inquisiive Problem Solver" ? I don't even know whether it's a magazine or website or what. Somehow I don't think I associate Sol LeWitt's name with the problem I'm trying to recall. It was posted by someone whose name I don't think I recognized then and don't recall now. (If you are that person, please forgive me.) But it had to do with 4x4 arrangements of black & white squares such that each row and each column contains 2 W and 2 B squares. The question was whether all such arrangements could be obtained in a certain way, which I don't remember, either. --Dan