3. Sequence Sum A sequence of integers such as 1,3,5,7,..can be represented by a function that takes a non-negative integer as parameter and returns the corresponding term of the sequence. For example, the sequence of odd numbers just cited can be represented by the function int odd (int k) (return 2 k1;) Write an abstract class Abstractseq that has a pure virtual member function virtual int fun (int k)0 as a stand-in for an actual sequence, and two member functions void printSeq (int k, int m); int sumSeq (int k, int m) that are passed two integer parameters k and m, where k