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Old 2013-05-25, 23:05   #4
Batalov
 
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"Serge"
Mar 2008
Phi(4,2^7658614+1)/2

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Quote:
Originally Posted by efeuvete View Post
I did not count numbers 1 and 2, that's all; 83284 with them, Ok.
1 is not a prime number, so your count is still one off.
You are probably skipping 2 and 5 based on your description. If so, then ok.

Your method seems to play with the properties of the Pisano periods. For some primes (see details on that Wiki page), the period will divide p-1, and consequently you will have F(p-1)=F(0)=0 (mod p), and for others, you will have F(p+1)=F(0)=0 (mod p). So, indeed, for the first rule, there shouldn't be false negative results other than 2 and 5.
Your pseudo's are probably numbers with low Pisano periods (including some Lucas numbers?), but I haven't looked in detail.

Last fiddled with by Batalov on 2013-05-25 at 23:48
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