OFFSET
1,1
EXAMPLE
29*3 = 87, neighboring primes are 83 and 89 which sum to 172; 173 is prime, hence 29 is in the sequence.
31*3 = 93, neighboring primes are 89 and 97 which sum to 186; neither 185 nor 187 is prime, hence 31 is not in the sequence.
1091*3 = 3273, neighboring primes are 3271 and 3299 which sum to 6570; both 6569 and 6571 are prime, hence 1091 is in the sequence.
PROG
(PARI) {m=360; forprime(p=2, m, d=3*p; k=precprime(d)+nextprime(d); if(isprime(k-1)||isprime(k+1), print1(p, ", ")))} /* Klaus Brockhaus, Jun 05 2007 */
CROSSREFS
KEYWORD
nonn
AUTHOR
J. M. Bergot, May 30 2007
EXTENSIONS
Edited and extended by Klaus Brockhaus, Jun 05 2007
STATUS
approved