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A127925 Primes p such that 2p < prime(k-i) + prime(k+i) for i=1..k-1, where p=prime(k). 2

%I

%S 3,7,19,23,43,47,73,109,113,199,283,293,313,317,463,467,503,509,523,

%T 619,661,683,691,887,1063,1069,1109,1129,1303,1307,1321,1327,1613,

%U 1621,1627,1637,1669,1789,2143,2161,2383,2393,2399,2477,2731,2753,2803,2861,2971

%N Primes p such that 2p < prime(k-i) + prime(k+i) for i=1..k-1, where p=prime(k).

%C One of several sets of "good primes" in section A14 of Guy.

%D R. K. Guy, Unsolved Problems in Number Theory, 3rd ed. Springer, 2004.

%H T. D. Noe, <a href="/A127925/b127925.txt">Table of n, a(n) for n=1..10001</a>

%t t={}; n=1; While[Length[t]<100, n++; p=Prime[n]; i=1; While[i<n && 2p<Prime[n-i]+Prime[n+i], i++ ]; If[i==n, AppendTo[t,p]]]; t

%Y Cf. A028388.

%K nonn

%O 1,1

%A _T. D. Noe_, Feb 06 2007

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Last modified October 14 14:36 EDT 2019. Contains 328019 sequences. (Running on oeis4.)