\magnification=1200 \hsize=4in \overfullrule=0pt \nopagenumbers \noindent % % {\bf Gregory Kucherov, Pascal Ochem and Micha\"el Rao} % % \medskip \noindent % % {\bf How Many Square Occurrences Must a Binary Sequence Contain?} % % \vskip 5mm \noindent % % % % Every binary word with at least four letters contains a square. A.~Fraenkel and J.~Simpson showed that three {\it distinct squares} are necessary and sufficient to construct an infinite binary word. We study the following complementary question: how many {\it square occurrences} must a binary word contain? We show that this quantity is, in the limit, a constant fraction of the word length, and prove that this constant is $0.55080...$. \bye .