Does the exponential diophantine equation $$ \prod x_i^{e_{x_i}} + \prod y_i^{e_{y_i}} = \prod z_i^{e_{z_i}}$$ with $x_i, y_i,z_i$ coprime and $e_{x_i}>3,e_{y_i}>3,e_{z_i}>3$ have solutions? Any solution will give a good $abc$ triple. After browsing the list of $abc$ triples I did not find a solution in the list. Any heuristics? The $abc$ [triple](http://www.math.leidenuniv.nl/~desmit/abc/?set=2) $7^2+2^{17} 181^2=3^8 809^2$ makes me ask: Does $$ x^2+y^{17}z^2=t^8u^2 $$ have infinitely many solutions with coprime $x,yz,tu$? Ideas about searching for solutions (I rediscovered the only known solution)?