+239 The terms of a particular sequence are determined according to the following rules:
* If the value of a given term is an odd positive integer s, then the value of the following term is 3s-9
* If the value of a given term is an even positive integer l, then the value of the following term is 2t-7.
Suppose that the terms of the sequence alternate between two positive integers (a, b, a, b, ...). What is the sum of the two positive integers?
