36311domain: NAppears in sequencesStrong pseudoprimes to base 84.at n=15A020310Largest number in a 6-tuple (a,b,c,d,e,f) of positive integers satisfying the Markoff(6) equation a^2 + b^2 + c^2 + d^2 + e^2 + f^2 = 3*a*b*c*d*e*f.at n=42A227204