Pépin's Test/Mistake
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Source Work
1997: David Wells: Curious and Interesting Numbers (2nd ed.):
- The Dictionary
- $257$
Mistake
- Such tests are easily performed today on computers using this criterion, which is similar to Lucas's test for the primality of Mersenne numbers: $F_n$ is prime if and only if it divides $3^{1/x \paren {F_n - 1} } + 1$.
Correction
That last expression should read $3^{\frac 1 2 \paren {F_n - 1} } + 1$, or more neatly: $3^{\paren {F_n - 1} / 2} + 1$.
This misprint was not present in the $1986$ edition of Curious and Interesting Numbers.
Sources
- 1997: David Wells: Curious and Interesting Numbers (2nd ed.) ... (previous) ... (next): $257$