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A260376 Values of n such that prime(prime(n)) + n is a prime number. 0
2, 6, 16, 20, 30, 42, 78, 90, 92, 102, 108, 118, 124, 126, 128, 132, 136, 150, 160, 166, 180, 182, 186, 194, 196, 202, 206, 210, 214, 230, 270, 280, 294, 348, 356, 358, 366, 370, 374, 378, 418, 436, 456, 458, 472, 474, 478, 492, 522, 546, 556, 560, 570, 584, 586, 590 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

Inspired by A061068.

Obviously, sequence only can include even numbers.

Initial primes of the form prime(prime(n)) + n are 7, 47, 257, 373, 647, 1129, 2797, 3389, 3499, 4129, 4447.

LINKS

Table of n, a(n) for n=1..56.

EXAMPLE

For n=2, prime(prime(2)) + 2 = prime(3) + 2 = 7. 7 is a prime number.

MATHEMATICA

Select[Range[600], PrimeQ[Prime[Prime[#]] + #] &] (* Vincenzo Librandi, Aug 30 2015 *)

PROG

(PARI) for(n=1, 1e3, if(isprime(prime(prime(n))+n), print1(n", ")))

(Magma) [n: n in [1..600] | IsPrime(NthPrime(NthPrime(n))+n)]; // Vincenzo Librandi, Aug 30 2015

(Perl) use ntheory ":all"; my @p = grep { is_prime(nth_prime(nth_prime($_))+$_) } 1..10000; say join ", ", @p; # Dana Jacobsen, Sep 02 2015

CROSSREFS

Cf. A006450.

Sequence in context: A080622 A082374 A085226 * A330866 A071522 A192532

Adjacent sequences: A260373 A260374 A260375 * A260377 A260378 A260379

KEYWORD

nonn,easy

AUTHOR

Altug Alkan, Aug 29 2015

STATUS

approved

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Last modified November 28 03:39 EST 2022. Contains 358406 sequences. (Running on oeis4.)