OFFSET
1,1
COMMENTS
All terms must necessarily be primes of the form 4n+3.
LINKS
Jens Kruse Andersen, Table of n, a(n) for n = 1..10000
EXAMPLE
MATHEMATICA
pythagPrimes = Select[4Range[500] + 1, PrimeQ]; len = Length[pythagPrimes]; pythagPrimeMeans = Table[(pythagPrimes[[n]] + pythagPrimes[[n + 1]])/2, {n, len - 1}]; Select[pythagPrimeMeans, PrimeQ] (* Alonso del Arte, Jul 12 2014 *)
PROG
(PARI)
p=[]; forstep(n=1, 8000, 4, if(isprime(n), p=concat(p, n))); p;
s=[]; for(k=1, #p-1, if(isprime(q=(p[k]+p[k+1])\2), s=concat(s, q))); s \\ Colin Barker, Jun 28 2014
CROSSREFS
KEYWORD
nonn
AUTHOR
Juri-Stepan Gerasimov, Jun 28 2014
EXTENSIONS
Several terms corrected or added by Colin Barker, Jun 28 2014
STATUS
approved