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A171708 Numbers k such that the k-th prime of the form 6*k-1 and the k-th prime of the form 6*k+1 are a pair of twin primes. 1
1, 2, 3, 6, 24 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..5.

FORMULA

{n: A007528(n) + 2 = A002476(n)}. A171713(n) = A007528(a(n)). - R. J. Mathar, Jun 07 2010

EXAMPLE

1 is in the sequence because the 1st primes of the forms 6*k-1 and 6*k+1(6*1-1=5 and 6*1+1=7, respectively) are a pair of twin primes;

2 is in the sequence because the 2nd primes (6*2-1=11 and 6*2+1=13) are a pair of twin primes;

3 is in the sequence because the 3rd primes (6*3-1=17 and 6*3+1=19) are a pair of twin primes;

6 is in the sequence because the 6th primes (6*7-1=41 and 6*7+1=43) are a pair of twin primes;

24 is in the sequence because the 24th primes (6*38-1=227 and 6*38+1=229) are a pair of twin primes.

CROSSREFS

Cf. A000027, A001097, A002476, A007528.

Sequence in context: A018300 A317973 A327013 * A329565 A295967 A027163

Adjacent sequences:  A171705 A171706 A171707 * A171709 A171710 A171711

KEYWORD

nonn

AUTHOR

Juri-Stepan Gerasimov, Dec 16 2009

EXTENSIONS

a(4) and a(5) corrected and a(6) removed by R. J. Mathar, Jun 07 2010

STATUS

approved

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Last modified March 28 20:01 EDT 2020. Contains 333103 sequences. (Running on oeis4.)