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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
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
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
KEYWORD
nonn,easy
AUTHOR
Jonathan Vos Post, Feb 15 2011
STATUS
approved