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A124662 Primes prime(n) such that there exists a 0 < k < n-1 such that prime(n+k) + prime(n-k) = 2*prime(n). 1
5, 11, 13, 17, 29, 31, 37, 41, 53, 59, 61, 67, 71, 83, 89, 97, 101, 103, 107, 127, 131, 137, 139, 151, 157, 167, 173, 179, 181, 191, 193, 197, 211, 233, 251, 257, 263, 277, 307, 311, 331, 337, 347, 349, 353, 359, 367, 373, 379, 383, 389, 397, 401, 409, 419, 421 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

prime(11+3) + prime(11-3) = 2*prime(11); therefore prime(11) = 31 is in the sequence.

LINKS

Table of n, a(n) for n=1..56.

MATHEMATICA

a = {}; For[k = 3, k < 100, k++, For[n = 1, n < k - 1, n++, If[(Prime[k + n] + Prime[k - n])/2 == Prime[k], AppendTo[a, Prime[k]]]]]; Union[a, a]

CROSSREFS

Sequence in context: A003632 A019354 A230288 * A226614 A191042 A049511

Adjacent sequences:  A124659 A124660 A124661 * A124663 A124664 A124665

KEYWORD

nonn

AUTHOR

Artur Jasinski, Dec 23 2006

EXTENSIONS

Edited, corrected and extended by Stefan Steinerberger, Jul 31 2007

STATUS

approved

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Last modified February 22 21:26 EST 2018. Contains 299469 sequences. (Running on oeis4.)