A256712 Primes prime(n) such that prime(2*n) - n is prime.

2, 3, 13, 29, 89, 113, 199, 229, 263, 281, 317, 337, 349, 541, 593, 673, 683, 827, 857, 911, 929, 971, 997, 1069, 1109, 1291, 1399, 1481, 1657, 1693, 1733, 1759, 1783, 1877, 1907, 1931, 2003, 2053, 2089, 2377, 2543, 2551, 2777, 2903, 3011, 3023, 3041, 3089, 3181, 3251, 3361, 3617, 3671

Offset

1,1

Comments

Primes prime(n) such that A031215(n) - n is prime.

Links

Table of n, a(n) for n=1..53.

Example

3 is in this sequence because 3 is prime(2) and prime(2*2) - 2 = prime(4)- 2 = 7 - 2 = 5 is prime.

Maple

seq(`if`(isprime(ithprime(2*n)-n), ithprime(n), NULL), n=1..1000); # Robert Israel, Apr 13 2015

Mathematica

Prime[Select[Range[555], PrimeQ[Prime[2*#]-#]&]] (* Ivan N. Ianakiev, Apr 14 2015 *)

Prog

(Magma) [NthPrime(n): n in [1..550] | IsPrime(NthPrime(2*n)-n)];
(PARI) for(n=1, 10^3, if(isprime(prime(2*n)-n), print1(prime(n), ", "))) \\ Derek Orr, Apr 14 2015

Crossrefs

Cf. A031215.

Sequence in context: A215379 A215375 A233523 * A092175 A317898 A317187

Adjacent sequences: A256709 A256710 A256711 * A256713 A256714 A256715

Keyword

nonn,easy

Author

Juri-Stepan Gerasimov, Apr 13 2015

Status

approved