A098029 Primes of the form (prime(k)+ prime(k+3))/2.

7, 23, 37, 47, 67, 73, 233, 277, 353, 479, 613, 631, 647, 809, 1097, 1283, 1297, 1433, 1453, 1471, 1493, 1607, 1613, 1663, 1709, 1721, 1783, 1867, 1889, 1901, 1931, 1993, 2099, 2137, 2161, 2377, 2383, 2411, 2521, 2621, 2683, 2693, 2713, 2797, 2879, 3049

Offset: 1

Author

Cino Hilliard, Sep 10 2004

Keywords

• easy
• nonn

Comments

The union of {7}, A119381 and A117876. - Irina Gerasimova, Jul 11 2013

Examples

			prime(2)=3, prime(2+3)=11. (3+11)/2 = 7
		

Links

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

Programs

Mathematica

Select[(#[[1]]+#[[4]])/2&/@Partition[Prime[Range[500]],4,1],PrimeQ] (* Harvey P. Dale, Nov 30 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",")))