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A023239 Primes p such that 10*p + 7 is also prime. 4
3, 13, 19, 31, 61, 67, 79, 97, 109, 127, 163, 199, 223, 229, 241, 277, 283, 313, 367, 379, 421, 433, 439, 463, 487, 523, 541, 547, 571, 619, 631, 673, 691, 751, 757, 787, 811, 823, 829, 853, 859, 883, 937, 967, 1033, 1093, 1117, 1171, 1237, 1249, 1291, 1303, 1321 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

John Cerkan, Table of n, a(n) for n = 1..10000

FORMULA

a(n) == 1 (mod 6), for n > 1. - John Cerkan, Sep 12 2016

MATHEMATICA

Select[Prime[Range[200]], PrimeQ[10# + 7] &] (* Alonso del Arte, Jun 24 2014 *)

PROG

(MAGMA) [n: n in [0..1000] | IsPrime(n) and IsPrime(10*n+7)] // Vincenzo Librandi, Nov 20 2010

CROSSREFS

Cf. A023238.

Subsequence of A102342.

Sequence in context: A117300 A023215 A185069 * A229494 A211438 A018621

Adjacent sequences:  A023236 A023237 A023238 * A023240 A023241 A023242

KEYWORD

nonn

AUTHOR

David W. Wilson

STATUS

approved

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Last modified September 21 16:31 EDT 2021. Contains 347598 sequences. (Running on oeis4.)