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Primes p such that ratio in A154754 is 3.
2

%I #2 Mar 30 2012 17:22:54

%S 7,13,19,61,73,79,103,109,127,139,151,163,193,199,211,241,271,307,337,

%T 349,373,409,421,523,541,547,571,607,613,673,739,757,769,787,811,853,

%U 877,883,907,919,937,967,991,1009,1033,1063,1087,1117,1123,1129,1201

%N Primes p such that ratio in A154754 is 3.

%C Note that all these primes have the form 6k+1, which is required for the equation x^2+x+1=0 (mod p) to have two integer solutions. However, this sequence has only about half of all 6k+1 primes. What other condition determines the p in this sequence? See A154755 for the primes not in this sequence.

%Y Cf. A000073

%K nonn

%O 1,1

%A _T. D. Noe_, Jan 15 2009