[tex]A=2^{2n+1}*3^{2n+3}-4^{n}*3^{2(n+1)}=2^{2n}*3^{2n}*2^{1}*3^{3}-2^{2n}*3^{2n}*3^{2}=(2*3)^{2n}*2*(27)-(2*3)^{2n}*9=36^{n}*54-36^{n}*9=36^{n}(54-9)=36^{n}*45[/tex]
Daca n>=1 atunci
[tex]A=36^{n-1}*36*45=36^{n-1}*6*6*45=36^{n-1}*6*270[/tex] care este evident divizibil cu 270