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How big are factorials?

99 points · 43 comments · ibobev

  1. emil-lp · · focus · HN ↗
    What's surprising (to many) is that

    n! < exp(n log n)

    1. Someone · · focus · HN ↗
      > What's surprising (to many) is that

      > n! < exp(n log n)

      Why would that be surprising? I can see that many wouldn’t know whether it’s true, but

        exp(n × log n) =
        exp(log(n) × n) =
        exp(log(n))^n =
        n^n
      
      and it’s not surprising that

          1 × 2 × 3 × 4 × … × n
        < n × n × n × n × … × n
      
      for n > 1
      1. emil-lp · · focus · HN ↗
        I don't know why that is surprising, but I'm teaching computer science at a university, and students seem surprised every time it comes up.
    2. [deleted] · · focus · HN ↗

      [deleted]

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