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.
%I A063909 #51 Mar 03 2025 09:32:00
%S A063909 5,11,17,23,29,47,53,59,71,89,101,131,137,149,179,197,227,233,257,263,
%T A063909 281,311,353,383,389,401,431,443,467,479,491,509,557,593,599,617,641,
%U A063909 647,653,683,719,743,809,821,857,863,941,947,953,977,1109
%N A063909 Primes p such that 2*p - 5 is also prime.
%C A063909 All terms are == 5 (mod 6). - _Zak Seidov_, Jan 07 2014
%C A063909 There are several interesting computer generated conjectures for this sequence at _Jon Maiga_'s Sequence Machine site. - _Antti Karttunen_, Dec 07 2021
%C A063909 Note that 5, p, 2p - 5 form an arithmetic progression (PAP-3). - _Charles R Greathouse IV_, Mar 03 2025
%H A063909 Antti Karttunen, <a href="/A063909/b063909.txt">Table of n, a(n) for n = 1..25000</a> (first 1000 terms from Harry J. Smith)
%H A063909 Jon Maiga, <a href="http://sequencedb.net/s/A063909">Computer-generated formulas for A063909</a>, Sequence Machine.
%F A063909 Intersection of A089253 and A000040. - _Michael B. Porter_, Jan 07 2014
%F A063909 a(n) = (A145471(n)+5)/2. [Also listed by Sequence Machine, and obviously true] - _Antti Karttunen_, Dec 07 2021
%e A063909 29 is in the sequence since p = 29 is prime and 2*p - 5 = 53 is also prime.
%t A063909 Select[Prime[Range[500]],PrimeQ[2#-5]&] (* _Harvey P. Dale_, Oct 10 2011 *)
%o A063909 (PARI) { n=0; p=1; for (m=1, 10^9, p=nextprime(p+1); if (isprime(2*p - 5), write("b063909.txt", n++, " ", p); if (n==1000, break)) ) } \\ _Harry J. Smith_, Sep 02 2009
%o A063909 (PARI) isA063909(p) = ((p%2)&&isprime(p)&&isprime(p+p-5)); \\ _Antti Karttunen_, Dec 07 2021
%o A063909 (PARI) list(lim)=my(v=List()); forprimestep(p=5,lim\1,6, if(isprime(2*p-5), listput(v,p))); Vec(v) \\ _Charles R Greathouse IV_, Mar 03 2025
%o A063909 (Magma) [p: p in PrimesUpTo(2000) | IsPrime(2*p-5)]; // _Vincenzo Librandi_, Feb 25 2016
%Y A063909 Subsequence of A007528 and hence A016969.
%Y A063909 Cf. A000040, A089253, A145471.
%K A063909 nonn,easy
%O A063909 1,1
%A A063909 _N. J. A. Sloane_, Aug 31 2001