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 A139404 #23 May 07 2025 14:58:06
%S A139404 0,1,4,6,8,11,19,34,44,51,53,54,78,81,83,89,93,96,99,106,116,141,144,
%T A139404 148,149,159,163,173,176,184,188,193,209,228,229,239,258,261,279,286,
%U A139404 306,316,323,328,331,351,358,368,369,389,393,394,401,403,418,429,446
%N A139404 Numbers k such that 24*k + 5 and 24*k + 7 are twin primes.
%C A139404 1/3 of number k such that 8k + 5 and 8k + 7 are primes.
%C A139404 All numbers in A125821 are divisible by 3.
%H A139404 Amiram Eldar, <a href="/A139404/b139404.txt">Table of n, a(n) for n = 1..10000</a>
%F A139404 a(n) = A125821(n)/3.
%e A139404 0 is in the sequence since 24*0 + 5 = 5 and 24*0 + 7 = 7 are twin primes.
%t A139404 a = {}; Do[If[PrimeQ[8 n + 5] && PrimeQ[8 n + 3] && PrimeQ[n],AppendTo[a, n]], {n, 1, 10000}]; a
%t A139404 Select[Range[0,500],AllTrue[24#+{5,7},PrimeQ]&] (* The program uses the AllTrue function from Mathematica version 10 *) (* _Harvey P. Dale_, Mar 08 2019 *)
%o A139404 (Magma) [n: n in [0..5000] |IsPrime(24*n+5)and IsPrime(24*n+7)]; // _Vincenzo Librandi_, Nov 24 2010
%Y A139404 Cf. A125822, A139402, A139404.
%K A139404 nonn
%O A139404 1,3
%A A139404 _Artur Jasinski_, Apr 19 2008
%E A139404 a(1) = 0 inserted by _Vincenzo Librandi_, Mar 25 2010