43468996857domain: NAppears in sequencesa(n) = 5*a(n - 1) - a(n - 2), with n>2, a(1)=2, a(2)=3.at n=16A164582Values of x in the solutions to x^2 - 5xy + y^2 + 17 = 0, where 0 < x < y.at n=31A237255