Prove that a sequence give by a recurrence relation converges











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let $b_n$ be a real sequence which satisfies



$b_{n+1}=(frac{1}{n^2}-frac{1}{2})b_n -frac{1}{3n^2}$, $b_1=frac{2}{3}$



I want to show that $b_n$ converges to $0$, which seems to be true according to my simulation.



I have tried to use some general ways to proof the convergence of a sequence like ratio test, but could not finish.










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    up vote
    1
    down vote

    favorite












    let $b_n$ be a real sequence which satisfies



    $b_{n+1}=(frac{1}{n^2}-frac{1}{2})b_n -frac{1}{3n^2}$, $b_1=frac{2}{3}$



    I want to show that $b_n$ converges to $0$, which seems to be true according to my simulation.



    I have tried to use some general ways to proof the convergence of a sequence like ratio test, but could not finish.










    share|cite|improve this question
























      up vote
      1
      down vote

      favorite









      up vote
      1
      down vote

      favorite











      let $b_n$ be a real sequence which satisfies



      $b_{n+1}=(frac{1}{n^2}-frac{1}{2})b_n -frac{1}{3n^2}$, $b_1=frac{2}{3}$



      I want to show that $b_n$ converges to $0$, which seems to be true according to my simulation.



      I have tried to use some general ways to proof the convergence of a sequence like ratio test, but could not finish.










      share|cite|improve this question













      let $b_n$ be a real sequence which satisfies



      $b_{n+1}=(frac{1}{n^2}-frac{1}{2})b_n -frac{1}{3n^2}$, $b_1=frac{2}{3}$



      I want to show that $b_n$ converges to $0$, which seems to be true according to my simulation.



      I have tried to use some general ways to proof the convergence of a sequence like ratio test, but could not finish.







      sequences-and-series convergence recurrence-relations






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          accepted










          Note that for all $varepsilon>0$, we have $|b_{n+1}|leqfrac 23|b_n|+varepsilon$ eventually, hence
          $$limsup |b_n|leq 3varepsilon$$






          share|cite|improve this answer























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            1 Answer
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            active

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            active

            oldest

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            active

            oldest

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            up vote
            0
            down vote



            accepted










            Note that for all $varepsilon>0$, we have $|b_{n+1}|leqfrac 23|b_n|+varepsilon$ eventually, hence
            $$limsup |b_n|leq 3varepsilon$$






            share|cite|improve this answer



























              up vote
              0
              down vote



              accepted










              Note that for all $varepsilon>0$, we have $|b_{n+1}|leqfrac 23|b_n|+varepsilon$ eventually, hence
              $$limsup |b_n|leq 3varepsilon$$






              share|cite|improve this answer

























                up vote
                0
                down vote



                accepted







                up vote
                0
                down vote



                accepted






                Note that for all $varepsilon>0$, we have $|b_{n+1}|leqfrac 23|b_n|+varepsilon$ eventually, hence
                $$limsup |b_n|leq 3varepsilon$$






                share|cite|improve this answer














                Note that for all $varepsilon>0$, we have $|b_{n+1}|leqfrac 23|b_n|+varepsilon$ eventually, hence
                $$limsup |b_n|leq 3varepsilon$$







                share|cite|improve this answer














                share|cite|improve this answer



                share|cite|improve this answer








                edited yesterday

























                answered yesterday









                Fabio Lucchini

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