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.
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