A squarefree term not occurring in the Leech sequence

03/27/2020

∙

by   Benjamin Wells, et al.

∙

0

∙

share

Let < a r r a y > The Leech sequence L is the squarefree sequence obtained as the limit of the palindromes A, A, A, ... . In order to specify a certain class of pseudorecursive varieties of semigroups, it is helpful to have a squarefree term in 3 variables such that no substitution instance occurs as a subterm of L. We show that κ_1 = aba cbc aba c is such a term. Except for one situation, the doubly-linked term κ_2 = aba cbc aba will serve, and we focus on it.