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Primes p such that 6*p + 1 is also prime.
(Formerly M0656)
22

%I M0656 #42 Feb 05 2024 00:59:18

%S 2,3,5,7,11,13,17,23,37,47,61,73,83,101,103,107,131,137,151,173,181,

%T 233,241,257,263,271,277,283,293,311,313,331,347,367,373,397,443,461,

%U 467,503,557,577,593,601,607,641,653,661,683,727,751,761,773,787,797,853

%N Primes p such that 6*p + 1 is also prime.

%D J. Roberts, Lure of the Integers, Math. Assoc. America, 1992, p. 27983

%D N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

%H Harvey P. Dale, <a href="/A007693/b007693.txt">Table of n, a(n) for n = 1..1000</a>

%H Andrew Granville, <a href="http://dx.doi.org/10.1016/0022-314X(87)90052-7">Sophie Germain's theorem for prime pairs p, 6p+1</a>, J. Number Theory 27 (1987), no. 1, 63-72.

%F a(n) = (A051644(n)-1)/6.

%t Select[Prime@Range[150], PrimeQ[6# + 1] &] (* _Ray Chandler_, Mar 14 2007 *)

%o (Magma) [n: n in [0..1000] | IsPrime(n) and IsPrime(6*n+1)]; // _Vincenzo Librandi_, Nov 18 2010

%Y Cf. A002476, A016921, A024899, A051644, A091178.

%Y Prime terms of A024899.

%K nonn,easy

%O 1,1

%A _N. J. A. Sloane_, _Robert G. Wilson v_

%E Extended by _Ray Chandler_, Mar 14 2007