OFFSET
1,1
COMMENTS
Primes that are not in A070299. - Franklin T. Adams-Watters, Nov 02 2014
LINKS
Charles R Greathouse IV, Table of n, a(n) for n = 1..373
EXAMPLE
2 is in this sequence because sigma(2-1) < sigma(2+1) and 2 is prime.
23 is not in the sequence because sigma(23-3) = sigma(23+3) = 42.
PROG
(PARI) forprime(p=1, 10^3, c=0; for(k=1, p-1, if(sigma(p+k)==sigma(p-k), c++; break)); if(!c, print1(p, ", "))) \\ Derek Orr, Nov 03 2014
(PARI) is(n)=forcomposite(c=15, n-1, if(sigma(c)==sigma(2*n-c), return(0))); isprime(n) \\ Charles R Greathouse IV, Nov 03 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Nov 02 2014
STATUS
approved