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A128653 Primes occurring in A084704 exactly twice. 3
43, 53, 59, 79, 113, 151, 163, 167, 197, 229, 269, 313, 331, 359, 367, 397, 419, 421, 449, 541, 607, 617, 619, 683, 719, 739, 757, 857, 883, 887, 907, 911, 997, 1021, 1051, 1063, 1103, 1117, 1193, 1249, 1289, 1303, 1427, 1433, 1459, 1471, 1489, 1493, 1499 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..49.

EXAMPLE

43 occurs as the 7th and 10th terms in A084704: ((prime(8)+43)/2 = (19+43)/2= 31 prime and ((prime(11)+43)/2 = (31+43)/2 = 37 prime;

53 is 9th and 12th terms in A084704: ((prime(10)+53)/2 = (29+53)/2 = 41 prime and ((prime(13)+53)/2 = (41+53)/2 = 47 prime.

CROSSREFS

For primes occurring in A084704 exactly 3 and 4 times see A128654, A128655. Cf. A084704 Smallest prime p > prime(n) such that (p+prime(n))/2 is prime.

Sequence in context: A162464 A255224 A161406 * A080104 A095744 A156252

Adjacent sequences:  A128650 A128651 A128652 * A128654 A128655 A128656

KEYWORD

nonn

AUTHOR

Zak Seidov, Mar 18 2007

STATUS

approved

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Last modified January 23 03:15 EST 2022. Contains 350504 sequences. (Running on oeis4.)