OFFSET
1,1
COMMENTS
Primes satisfying sigma(2p+1)-sigma(p)=p+1 are Sophie Germain primes A005384(n)
PROG
(PARI) for(n=1, 500000000, if((sigma(2*n+1)-sigma(n)==n+1) && (!isprime(n)), print1(n, ", ")))
CROSSREFS
KEYWORD
easy,nonn
AUTHOR
Benoit Cloitre, Feb 28 2002
EXTENSIONS
More terms from Rick L. Shepherd, May 08 2002
STATUS
approved