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

1,1

Comments

Primes of the form A299644(k)/2. - Amiram Eldar, Jul 08 2024

Links

Amiram Eldar, Table of n, a(n) for n = 1..10000

Example

prime(prime(18)) = 283, prime(prime(19)) = 331. (283 + 331)/2 = 614/2 = 307.

Mathematica

With[{t = Table[Prime[Prime[n]], {n, 1, 400}]}, Select[(Most[t] + Rest[t])/2, PrimeQ]] (* Amiram Eldar, Jul 08 2024 *)

Prog

(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", ")))

Crossrefs

Cf. A006450, A098043, A299644.

Sequence in context: A261289 A142255 A309101 * A125252 A308785 A142572

Adjacent sequences: A098039 A098040 A098041 * A098043 A098044 A098045

Keyword

easy,nonn

Author

Cino Hilliard, Sep 10 2004

Extensions

Offset corrected by Amiram Eldar, Jul 08 2024

Status

approved