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Primes p such that m=p-1 is the least number such that p divides m!+1.
2

%I #3 Mar 30 2012 17:22:54

%S 2,3,5,13,17,31,37,41,53,73,89,97,101,107,113,151,157,167,173,181,197,

%T 211,223,229,241,281,283,313,331,337,349,353,373,409,421,433,439,457,

%U 487,509,541,547,587,617,643,653,659,677,701,751,757,761,769,773,821

%N Primes p such that m=p-1 is the least number such that p divides m!+1.

%C The graph of A073944 shows two prominent curves. This sequence gives the primes on the upper curve. Primes on the lower curve are in sequence A154555. Note that the terms of A115092 are 1 for these primes.

%H T. D. Noe, <a href="/A154554/b154554.txt">Table of n, a(n) for n=1..1000</a>

%t Rest[Reap[Do[p=Prime[i]; f=1; m=1; While[f=Mod[f*m,p]; f+1<p, m++ ]; If[m==p-1, Sow[p]], {i,200}]]][[1,1]]

%K nonn

%O 1,1

%A _T. D. Noe_, Jan 12 2009