Let the sequence {an}n≥1 be defined by a_1 \equal{} 20, a_2 \equal{} 30 and a_{n \plus{} 2} \equal{} 3a_{n \plus{} 1} \minus{} a_n for all n≥1. Find all positive integers n such that 1 \plus{} 5a_n a_{n \plus{} 1} is a perfect square. inductionalgebrabinomial theoremalgebra solved