Résumé
A long standing question asks whether Z is uniformly 2-repetitive, that is, whether or not there is an infinite sequence over a finite subset of Z avoiding two consecutive blocks of the same size and same sum [J. Justin, J. Combin. Theory Ser. A, 12 (1972), pp. 357-367], [G. Pirillo and S. Varricchio, Semigroup Forum, 49 (1994), pp. 125-129]. Cassaigne et al. [J. ACM, 61 (2014), 10] showed that Z is not uniformly 3-repetitive. We show that Z(2) is not uniformly 2-repetitive. Moreover, this problem is related to a question from Makela in combinatorics on words, and we answer a weak version of it.