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 A126107 #16 Aug 10 2025 00:49:11
%S A126107 2,5,29,53,89,113,173,509,659,743,809,1013,1499,1559,1583,1733,2063,
%T A126107 2129,2273,2393,2399,2549,2819,2939,3329,3389,3413,3779,4409,5003,
%U A126107 5849,6053,6269,7193,7433,7643,7823,8069,8093,8513,8693,9029,9059,9539,9689
%N A126107 Primes p such that 2*p+1 and 2*p+3 are twin primes.
%H A126107 Vincenzo Librandi, <a href="/A126107/b126107.txt">Table of n, a(n) for n = 1..1000</a>
%e A126107 a(2)=5 because 2*5+1=11 and 2*5+3=13 are twin primes.
%t A126107 Do[p = Prime[ i]; If[PrimeQ[2p + 1] && PrimeQ[2p + 3], Print[p]], {i, 1, 2000}] (* _Michael Taktikos_, Apr 01 2007 *)
%t A126107 Select[Prime[Range[10000]], PrimeQ[2 # + 1] && PrimeQ[2 # + 3] &] (* _Vincenzo Librandi_, Feb 15 2014 *)
%o A126107 (Magma) [p: p in PrimesUpTo(10000) | IsPrime(2*p+1) and IsPrime(2*p+3)]; // _Vincenzo Librandi_, Feb 15 2014
%o A126107 (PARI) is(p)=isprime(2*p+1) && isprime(2*p+3) && isprime(p) \\ _Charles R Greathouse IV_, Mar 03 2018
%o A126107 (PARI) list(lim)=my(v=List(),p=3); forprime(q=5,2*lim+3, if(q-p==2 && isprime(p\2), listput(v,p\2)); p=q); Vec(v) \\ _Charles R Greathouse IV_, Mar 03 2018
%Y A126107 Cf. A128436 (primes p such that 2*p-3 and 2*p-1 are twin primes).
%K A126107 nonn,easy
%O A126107 1,1
%A A126107 _Zak Seidov_, Mar 05 2007