Prove $a_n = lfloor ni rfloor$ for some irrational $i$ has no pattern












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I have a sequence $a_n = lfloor ni rfloor$ for an irrational $i$ and I want to prove that there is no 'pattern' to these terms.



In particular, I have $1 < i <2$ and I want to prove that $forall a,b in mathbb{N}, exists k in mathbb{N}$ such that $a +bk neq a_n$ for any $n$.

This makes sense to me intuitively because $a_n - a_{n-1}$ will be 1 or 2 'randomly', so the sequence must eventually 'skip over' one of the terms of $a+bk$.



My approach has been to assume that it holds, then show that $i$ must be rational for a contradiction. However, the floor is messing up the simple divisibility techniques I would use.










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    4












    $begingroup$


    I have a sequence $a_n = lfloor ni rfloor$ for an irrational $i$ and I want to prove that there is no 'pattern' to these terms.



    In particular, I have $1 < i <2$ and I want to prove that $forall a,b in mathbb{N}, exists k in mathbb{N}$ such that $a +bk neq a_n$ for any $n$.

    This makes sense to me intuitively because $a_n - a_{n-1}$ will be 1 or 2 'randomly', so the sequence must eventually 'skip over' one of the terms of $a+bk$.



    My approach has been to assume that it holds, then show that $i$ must be rational for a contradiction. However, the floor is messing up the simple divisibility techniques I would use.










    share|cite|improve this question











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      4












      4








      4


      1



      $begingroup$


      I have a sequence $a_n = lfloor ni rfloor$ for an irrational $i$ and I want to prove that there is no 'pattern' to these terms.



      In particular, I have $1 < i <2$ and I want to prove that $forall a,b in mathbb{N}, exists k in mathbb{N}$ such that $a +bk neq a_n$ for any $n$.

      This makes sense to me intuitively because $a_n - a_{n-1}$ will be 1 or 2 'randomly', so the sequence must eventually 'skip over' one of the terms of $a+bk$.



      My approach has been to assume that it holds, then show that $i$ must be rational for a contradiction. However, the floor is messing up the simple divisibility techniques I would use.










      share|cite|improve this question











      $endgroup$




      I have a sequence $a_n = lfloor ni rfloor$ for an irrational $i$ and I want to prove that there is no 'pattern' to these terms.



      In particular, I have $1 < i <2$ and I want to prove that $forall a,b in mathbb{N}, exists k in mathbb{N}$ such that $a +bk neq a_n$ for any $n$.

      This makes sense to me intuitively because $a_n - a_{n-1}$ will be 1 or 2 'randomly', so the sequence must eventually 'skip over' one of the terms of $a+bk$.



      My approach has been to assume that it holds, then show that $i$ must be rational for a contradiction. However, the floor is messing up the simple divisibility techniques I would use.







      sequences-and-series irrational-numbers






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      edited Jan 21 at 3:00







      MannerPots

















      asked Jan 20 at 23:43









      MannerPotsMannerPots

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          This is a case of the equidistribution theorem. If the sequence repeats, subdivide $[0,1]$ finely enough and some pieces will get nothing.






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            1 Answer
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            active

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            4












            $begingroup$

            This is a case of the equidistribution theorem. If the sequence repeats, subdivide $[0,1]$ finely enough and some pieces will get nothing.






            share|cite|improve this answer









            $endgroup$


















              4












              $begingroup$

              This is a case of the equidistribution theorem. If the sequence repeats, subdivide $[0,1]$ finely enough and some pieces will get nothing.






              share|cite|improve this answer









              $endgroup$
















                4












                4








                4





                $begingroup$

                This is a case of the equidistribution theorem. If the sequence repeats, subdivide $[0,1]$ finely enough and some pieces will get nothing.






                share|cite|improve this answer









                $endgroup$



                This is a case of the equidistribution theorem. If the sequence repeats, subdivide $[0,1]$ finely enough and some pieces will get nothing.







                share|cite|improve this answer












                share|cite|improve this answer



                share|cite|improve this answer










                answered Jan 21 at 3:14









                Ross MillikanRoss Millikan

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