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How can we compute the value of $\mathrm{gcd}(2^n-1,n!)$ efficiently where $n$ is very large? I couldn't think of any fast and efficient method.

  • 1
    How large is very large? n=1000? n=1000000?2011-01-31
  • 0
    TonyK : ~10^5 . .2011-02-01

2 Answers 2