It is well known that for a sequence a = ($a_0,;a_1$,...) the general term of the dual sequence of a is $a_n;=;c_0;^n_0;+;c_1;^n_1;+;...;+;c_n;^n_n$, where c = ($c_0,...c_n$ is the dual sequence of a. In this paper, we find the general term of the sequence ($c_0,;c_1$,... ) and give another method for finding the inverse matrix of the Pascal matrix. And we find a simple proof of the fact that if the general term of a sequence a = ($a_0,;a_1$,... ) is a polynomial of degree p in n, then ${Delta}^{p+1}a;=;0$.