Cohen-Macaulay local rings with e2 = e1 − e + 1

In this paper we study Cohen-Macaulay local rings of dimension d, multiplicity e and second Hilbert coefficient e2 in the case e2=e1−e+1. Let h=μ(m)−d. If e2≠0 then our can prove that type(A)≥e−h−1. type(A)=e−h−1 show associated graded ring G(A) is Cohen-Macaulay. next when type(A)=e−h determine all possible series A. depthG(A) completely determines Series