Wieferich Prime

Author

Eric W. Weisstein
November 3, 2005

This notebook downloaded from http://mathworld.wolfram.com/notebooks/PrimeNumbers/WieferichPrime.nb.

For more information, see Eric's MathWorld entry http://mathworld.wolfram.com/WieferichPrime.html.

©2005 Wolfram Research, Inc. except for portions noted otherwise

Code

WieferichPrimeQ[p_]:=PowerMod[2,p-1,p^2]==1

Enumeration

Only known examples

WieferichPrimeQ/@{1093,3511}

Select[Prime[Range[10^5]],WieferichPrimeQ]//Timing

Select[Prime[Range[10^6]],WieferichPrimeQ]//Timing

Select[Prime[Range[10^6,2 10^6]],WieferichPrimeQ]//Timing

Digits[3511]