Răspuns :
a)[tex]a=( 2^{2n+2}) ^{n+1} +1=[( 2^{2}) ^{n+1}] ^{n+1} +1= (4^{n+1}) ^{n+1} +1= 4^{ (n+1)^{2} } +1[/tex] este p.p.
a) a = 2^2n + 2·2^n + 1 = (2^n + 1)²
b) a = 3^2n + 2³ ·3^n + 2^4 = (3^n)² + 2·(2² ·3^n) + (2²)²= (3^n +4)² = p.p
b) a = 3^2n + 2³ ·3^n + 2^4 = (3^n)² + 2·(2² ·3^n) + (2²)²= (3^n +4)² = p.p