OFFSET
1,2
EXAMPLE
PROG
(PARI) for(n=1, 1e4, if(isprime(6*n-1)&&isprime(6*n+1)&&isprime(sigma(6*n)-1)&&isprime(sigma(6*n)+1), print1(n", "))) \\ Charles R Greathouse IV, Dec 26 2011
CROSSREFS
KEYWORD
nonn,less
AUTHOR
Juri-Stepan Gerasimov, Dec 21 2011
STATUS
approved