Finitely generated parafree group

Definition
A group is termed a finitely generated parafree group if it is both a finitely generated group and a parafree group. Note that the free group that this finitely generated parafree group has the same lower central series as is a finitely generated free group, and further, its rank is determined by the isomorphism type of the parafree group (explicitly, it equals the rank of the abelianization of the parafree group).