On the Upper Bound of the Third Hankel Determinant for Certain Class of Analytic Functions Related with Exponential Function

In the present paper we introduce a new class of analytic functions f in the open unit disk normalized by f (0) = f ′ (0) − 1 = 0, associated with exponential functions. The aim of the present paper is to investigate the third-order Hankel determinant H 3 (1) for this function class and obtain the upper bound of the determinant H 3 (1).