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%I #31 Sep 08 2022 08:44:47
%S 2,3,5,11,17,23,41,47,53,71,83,113,131,137,173,191,197,227,251,257,
%T 281,293,317,347,383,401,461,467,503,521,587,593,641,647,677,683,701,
%U 743,773,797,857,863,941,947,953,971,983,1031,1061,1103,1151,1163,1187,1193,1217
%N Numbers m such that m and 2*m + 7 both prime.
%C Subsequence of A105760. Except for the first two terms, all terms are congruent to 5 mod 6. - _John Cerkan_, Sep 07 2016
%H Vincenzo Librandi, <a href="/A023206/b023206.txt">Table of n, a(n) for n = 1..1000</a>
%p A023206:=n->`if`(isprime(n) and isprime(2*n+7), n, NULL): seq(A023206(n), n=1..3*1000); # _Wesley Ivan Hurt_, Sep 07 2016
%t Select[Prime@Range@250,PrimeQ[2#+7]&] (* _Vladimir Joseph Stephan Orlovsky_, Apr 25 2011 *)
%o (Magma) [n: n in [0..1000] | IsPrime(n) and IsPrime(2*n+7)]; // _Vincenzo Librandi_, Nov 20 2010
%o (PARI) is(n)=isprime(2*n+7) && isprime(n) \\ _Charles R Greathouse IV_, Sep 07 2016
%Y Cf. A005384, A023204, A023205.
%K nonn,easy
%O 1,1
%A _David W. Wilson_
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