306268562domain: NAppears in sequencesImaginary part of (1+2i)^n.at n=25A006496Real part of (2 + i)^n, where i = sqrt(-1).at n=25A139011Values of x such that x^2 + y^2 = 5^n with x and y coprime and 0 < x < y.at n=24A230710