98248054847domain: NAppears in sequencesSmallest leg in right triangle with relatively prime sides and hypotenuse 5^n.at n=15A036842a(1) = 1, a(2) = 2; thereafter a(2n+1) = |a(2n)^2-a(2n-1)^2|, a(2n+2) = 2*a(2n-1)*a(2n).at n=10A100686Values of x such that x^2 + y^2 = 5^n with x and y coprime and 0 < x < y.at n=31A230710