OFFSET
1,1
COMMENTS
20*n's are in A002822 = numbers n such that 6n-1, 6n+1 are twin primes.
LINKS
Zak Seidov, Table of n, a(n) for n = 1..5746 (Terms < 100000)
MATHEMATICA
Select[Range[500], AllTrue[120#+{-1, 1}, PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* Harvey P. Dale, Mar 01 2019 *)
PROG
(PARI) isok(n) = isprime(120*n-1) && isprime(120*n+1); \\ Michel Marcus, Oct 11 2013
CROSSREFS
KEYWORD
nonn
AUTHOR
Zak Seidov, Oct 28 2006
STATUS
approved