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A186243 Numbers n such that 6n-5 and 6n-1 are both primes. 8
2, 3, 4, 7, 8, 12, 14, 17, 18, 19, 22, 28, 33, 38, 39, 47, 52, 53, 59, 64, 67, 74, 77, 78, 82, 84, 103, 108, 113, 124, 127, 129, 138, 143, 144, 147, 148, 152, 157, 162, 169, 182, 183, 203, 214, 217, 218, 238, 239, 242, 248, 249, 259, 262, 264, 267, 269 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Numbers n such that 6n-5 and 6n-1 are cousin primes. The D = 2 numbers in class II, from page 3 of Weber. - Jonathan Vos Post, Feb 14 2011

LINKS

Ivan Neretin, Table of n, a(n) for n = 1..10000

H. J. Weber, Exceptional Prime Number Twins, Triplets and Multiplets, arXiv:1102.3075 [math.NT], 2011.

Eric W. Weisstein, Cousin Primes.

FORMULA

{n such that 6*n-5 is in A023200} = {n such that 6*n-1 is in A046132}.

EXAMPLE

a(3) = 4 because 6*4-5 = 19 is prime, and 6*4-1 = 23 is prime.

MATHEMATICA

Select[Range[400], PrimeQ[6#-5] && PrimeQ[6#-1] &] (* Alonso del Arte, Feb 16 2011 *)

CROSSREFS

Cf. A023200, A046132, A088765.

Sequence in context: A078662 A050048 A122456 * A073882 A015840 A051213

Adjacent sequences:  A186240 A186241 A186242 * A186244 A186245 A186246

KEYWORD

nonn,easy

AUTHOR

Jonathan Vos Post, Feb 15 2011

STATUS

approved

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Last modified April 6 21:24 EDT 2020. Contains 333286 sequences. (Running on oeis4.)