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A023205 Numbers m such that m and 2*m + 5 are both prime.

%I A023205 #36 Sep 08 2022 08:44:47
%S A023205 3,7,13,19,31,37,61,67,73,79,97,103,109,139,151,163,181,229,241,271,
%T A023205 283,307,313,367,373,409,439,457,523,541,613,643,661,709,727,733,739,
%U A023205 769,787,811,829,859,877,937,991,997,1039,1063,1069,1087,1117,1123,1153,1171
%N A023205 Numbers m such that m and 2*m + 5 are both prime.
%H A023205 John Cerkan, <a href="/A023205/b023205.txt">Table of n, a(n) for n = 1..10000</a>
%F A023205 a(n) == 1 (mod 6) for n>=2. - _John Cerkan_, Sep 07 2016
%p A023205 A023205:=n->`if`(isprime(n) and isprime(2*n+5), n, NULL): seq(A023205(n), n=1..3*10^3); # _Wesley Ivan Hurt_, Sep 08 2016
%t A023205 Select[Prime@Range@250, PrimeQ[2#+5]&] (* _Vladimir Joseph Stephan Orlovsky_, Apr 25 2011 *)
%o A023205 (Magma) [n: n in [0..100000] | IsPrime(n) and IsPrime(2*n+5)] // _Vincenzo Librandi_, Aug 04 2010
%Y A023205 Subsequence of primes of A089038.
%Y A023205 Cf. A005384, A023204.
%K A023205 nonn
%O A023205 1,1
%A A023205 _David W. Wilson_, Jun 14 1998