OFFSET
1,1
LINKS
Robert Israel, Table of n, a(n) for n = 1..10000
EXAMPLE
a(3)=47 is a term because it is prime, the next prime is 53, and (3*47+53)/2 = 97 and (47+3*53)/2 = 103 are both prime.
MAPLE
Primes:= [seq(ithprime(i), i=1..10000)]:
Res:= NULL:
for i from 2 to nops(Primes)-1 do
p:= Primes[i]; q:= Primes[i+1]; c:= (p+q)/2;
if isprime(p+c) and isprime(q+c) then
Res:= Res, p
fi
od:
Res;
CROSSREFS
KEYWORD
nonn
AUTHOR
J. M. Bergot and Robert Israel, Feb 25 2020
STATUS
approved