Let <math>\text{p}_i</math> be the <math>i^\text{th}</math> prime, where <math>i</math> is a positive integer called the ''index'' of the prime <math>\text{p}_i</math> and the indices are taken such that <math>\text{p}_1 = 2.</math> Thus the sequence <math>\text{p}_i</math> begins as follows:
+
Let <math>\text{p}_i</math> be the <math>i^\text{th}</math> prime, where the positive integer <math>i</math> is called the ''index'' of the prime <math>\text{p}_i</math> and the indices are taken in such a way that <math>\text{p}_1 = 2.</math> Thus the sequence of primes begins as follows: