7421875domain: NAppears in sequencesa(n) = Sum_{k=0..n} (k+1) * T(n,k), with T given by A026374.at n=17A026950a(n) = Sum_{k=0..n} (k+1) * T(n,k), with T given by A026386.at n=17A026955Hypotenuses for which there exist exactly 8 distinct integer triangles.at n=13A290499