Page 54 -
P. 54

IV. Sequences without Arithmetic Progressions
                        48
                        Problems for Chapter IV
                        1. Attach a positive rational to each integer from 1 to 12 so that all
                           A.P.’s with common difference d up to 6 obtain their “correct”
                           measure  1  .
                                    d
                        2. Prove that, if we ask for a generalization of this, then we can only
                           force the correct measure  1  for all A.P.’s of common difference
                                                     d                        √
                           d, by attaching weights onto 1, 2,...,è, if d   O( n).
                        3. If we insist only on approximation, however, show that we can
                           always attach weights onto 1, 2,...,è such that the “measure”
                           given to every A.P. with common difference ≤ m is within e −n/m
                           of  1  .
                              a
   49   50   51   52   53   54   55   56   57   58   59