cp's OEIS Frontend

This is a front-end for the Online Encyclopedia of Integer Sequences, made by Christian Perfect. The idea is to provide OEIS entries in non-ancient HTML, and then to think about how they're presented visually. The source code is on GitHub.

A104163 Primes p such that (2p+1)/3 is prime.

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%I A104163 #20 Mar 12 2014 16:36:45
%S A104163 7,19,43,61,79,109,151,163,223,271,349,421,439,523,601,613,631,673,
%T A104163 691,811,853,919,991,1009,1051,1063,1153,1213,1231,1279,1321,1429,
%U A104163 1531,1549,1663,1693,1789,1801,1873,1933,1951,2113,2143,2179,2221,2239,2503,2539
%N A104163 Primes p such that (2p+1)/3 is prime.
%C A104163 Dickson's conjecture implies that this sequence is infinite. - _Charles R Greathouse IV_, Jul 31 2012
%H A104163 Vincenzo Librandi, <a href="/A104163/b104163.txt">Table of n, a(n) for n = 1..1000</a>
%F A104163 a(n)=(3*A158708(n+1)-1)/2 _Zak Seidov_, Jul 31 2012
%e A104163 7 is in the sequence because (2 * 7 + 1)/3 = 5, which is also prime.
%e A104163 19 is in the sequence because (2 * 19 + 1)/3 = 13, which is also prime.
%t A104163 Select[Range[7, 2539, 2], PrimeQ[#] && PrimeQ[(2# + 1)/3]&] (* _Zak Seidov_, Jul 31 2012 *)
%t A104163 Select[Prime[Range[400]], PrimeQ[(2 # + 1) / 3]&] (* _Vincenzo Librandi_, Apr 14 2013 *)
%o A104163 (PARI) is(n)=n%3==1 && isprime((2*n+1)/3) && isprime(n) \\ _Charles R Greathouse IV_, Jul 31 2012
%Y A104163 Cf. A005384.
%K A104163 nonn,easy
%O A104163 1,1
%A A104163 _Roger L. Bagula_, Mar 10 2005
%E A104163 New name from _Charles R Greathouse IV_, Jul 31 2012