A098042 Primes of the form (prime(prime(k)) + prime(prime(k+1)))/2.
307, 593, 1459, 1511, 1609, 2399, 2447, 2579, 2903, 4409, 5953, 6317, 7151, 11083, 12491, 14753, 16067, 18199, 18223, 20929, 21787, 23893, 25667, 26317, 31051, 37139, 37573, 37871, 40283, 40471, 41201, 41479, 42013, 44537, 44741, 48409
Offset: 1
Examples
prime(prime(18)) = 283, prime(prime(19)) = 331. (283 + 331)/2 = 614/2 = 307.
Links
- Amiram Eldar, Table of n, a(n) for n = 1..10000
Programs
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Mathematica
With[{t = Table[Prime[Prime[n]], {n, 1, 400}]}, Select[(Most[t] + Rest[t])/2, PrimeQ]] (* Amiram Eldar, Jul 08 2024 *) -
PARI
lista(n) = for(x=1,n,y=prime(prime(x+1))+prime(prime(x)); if(y%2==0&isprime(y/2),print1(y\2",")))
Extensions
Offset corrected by Amiram Eldar, Jul 08 2024
Comments