37641223154domain: NAppears in sequencesReal part of (2 + 3i)^n.at n=19A121621List of coprime pairs (x,y) such that x^2+y^2 = 13^n with 0<x<y.at n=39A158936Values of y such that x^2 + y^2 = 13^n with x and y coprime and 0 < x < y.at n=19A188949Even numbers x such that x^2 + y^2 = 13^n with x and y coprime.at n=19A188982