A098031 Primes p such that p = (prime(n)+ prime(n+4))/2.

11, 13, 17, 103, 107, 151, 179, 251, 409, 421, 491, 619, 701, 709, 739, 941, 1009, 1051, 1069, 1459, 1487, 1499, 1571, 1759, 1789, 1873, 2281, 2441, 2659, 2671, 2741, 2749, 2789, 2819, 2861, 3011, 3019, 3331, 3389, 3463, 3931, 4001, 4111, 4177, 4229, 4231

Offset: 1

Author

Cino Hilliard, Sep 10 2004

Keywords

• easy
• nonn

Comments

The union of sequences A179208, A118467, and A126238. - Irina Gerasimova, Jul 07 2013

Examples

			prime(3)=5,prime(3+4)=17. (5+17)/2 = 11.
		

Links

• Harvey P. Dale, Table of n, a(n) for n = 1..1000

Programs

Mathematica

Select[Table[(Prime[n]+Prime[n+4])/2,{n,800}],PrimeQ] (* Harvey P. Dale, Sep 29 2017 *)

PARI

f(n,m) = for(x=1,n,y=prime(x)+prime(x+m);if(y%2==0 & isprime(y\2), print1(y\2",")))