905768domain: NAppears in sequencesa(n) = 17^n sin(2n arctan(1/4)) or numerator of tan(2n arctan(1/4)).at n=4A067360Expansion of 1/(1 - 8x + 17x^2).at n=9A106393Values of x such that x^2 + y^2 = 17^n with x and y coprime and 0 < x < y.at n=9A230622