报告人：Jean-Paul Allouche（巴黎六大）

邀请人：胡怡宁

报告时间：2021年4月29日(星期四)16:30-18:30

报告地点：Zoom Id : 611 823 1216 密码: KikLh8

报告题目：Hidden automatic sequences

报告摘要：We discuss a joint work with Michel Dekking and MartinQueffélec(https://arxiv.org/abs/2010.00920) about sequences given as fixedpoints of non-uniform morphisms that happen to be actually automatic.One of the most ancien example is probably the one due to Berstel, who proved that the Istrail squarefree sequence defined as the fixed point ofthe morphism ff with f(0)=12f(0)=12f(1)=102f(1)=102, f(2)=0f(2)=0, is also 22-automatic.After revisiting an old criterion due to M. Dekking at the end of the 70's, we give several examples (in particular of sequences in the OEIS). Finally we focus on morphisms associated with Grigorchuk(-like) groups.