In this article, we introduce a new sequence to find a new estimation of the cardinality N-m of the minimal involutive square-free solution of level m. As an application, using the first values of we improve the estimations of N-m obtained by Gateva-Ivanova and Cameron and Lebed and Vendramin. Following the approach of the first part, in the last section we construct several new counterexamples to the Gateva-Ivanova's Conjecture.