2366428705domain: NAppears in sequencesValues of c in a^2 + b^2 = c^2, where b - a = 17 and gcd(a,b,c)=1.at n=21A117472a(n) = 6*a(n-1)-a(n-2) for n > 2; a(1) = 13, a(2) = 53.at n=11A156156