334668domain: NAppears in sequencesNumbers k whose digits can be divided into two contiguous parts, k = concatenate(x, y), such that k = |x^2 - y^2|.at n=13A113797Numbers k which are concatenations k=x//y such that x^2 + y^2 - x*y = k.at n=31A162556Numbers k which are concatenations k = x//y such that y^2 - x^2 = k.at n=9A162700