Talk:Lucas-Lehmer Test
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I always thought 11 was a prime. Guess not. If q=11 Excel says L9 is 1736.
- Yes, that is perfectly correct. $11$ is prime. However, $2^{11} - 1$ is not prime ($2047 = 23 \times 89$), which is why $L_9 \ne 0$. --prime mover 22:14, 18 September 2010 (UTC)
