An infinite family of finite ۲-groups with fixed co-class

In [۱] six pro-۲-groups of finite and fixed coclasses is studied. Infinite sequences of finite ۲-groups arising from this pro۲-groups also investigated. One of the five infinite sequences associated with the pro-۲-group S = ha, u | a ۲ = u ۴ ,(u ۲ ) a = u −۲ i is the sequence Gj (۱, ۲) = ha, u | a ۲ u −۴ (u −۱ a) ۲ j ,(u ۲ ) a u ۲ (u −۱ a) ۲ j+۱ ,(u −۱ a) ۲ j+۲ i. In this paper we calculate the orders of the members of this infinite family