Simplify the following text for a Grade 12 native English-speaking person.
Original: It is also a Stern prime , a Pell number , the first Fibonacci prime , and a Markov number , appearing in infinitely many solutions to the Markov Diophantine equation involving odd-indexed Pell numbers .
Simplified: It is also a Stern prime , a Pell number , and a Markov number , appearing in infinitely many solutions to the Markov Diophantine equation involving odd-indexed Pell numbers .