OFFSET
1,1
LINKS
Amiram Eldar, Table of n, a(n) for n = 1..10000
EXAMPLE
k = 2 is a term since 210*2 - 1 = 419 and 210*2 + 1 = 421 are twin primes.
MATHEMATICA
Select[Range[6! ], PrimeQ[210*#-1]&&PrimeQ[210*#+1]&] (* Vladimir Joseph Stephan Orlovsky, Apr 08 2010 *)
PROG
(PARI) isok(n) = isprime(210*n+1) && isprime(210*n-1); \\ Michel Marcus, Jan 14 2015
(Magma) [k:k in [1..320]| IsPrime(210*k-1) and IsPrime(210*k+1)]; // Marius A. Burtea, Jan 01 2020
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Zak Seidov, Oct 08 2002
STATUS
approved