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

3, 7, 19, 23, 43, 47, 73, 109, 113, 199, 283, 293, 313, 317, 463, 467, 503, 509, 523, 619, 661, 683, 691, 887, 1063, 1069, 1109, 1129, 1303, 1307, 1321, 1327, 1613, 1621, 1627, 1637, 1669, 1789, 2143, 2161, 2383, 2393, 2399, 2477, 2731, 2753, 2803, 2861, 2971

Offset

1,1

Comments

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

References

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

Links

T. D. Noe, Table of n, a(n) for n=1..10001

Mathematica

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

Crossrefs

Cf. A028388.

Sequence in context: A322963 A018432 A205302 * A032388 A050866 A226923

Adjacent sequences: A127922 A127923 A127924 * A127926 A127927 A127928

Keyword

nonn

Author

T. D. Noe, Feb 06 2007

Status

approved