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 A074039 #9 Apr 06 2025 08:46:18
%S A074039 0,0,1,0,2,0,0,0,0,0,3,0,0,0,0,0,4,0,0,0,0,0,0,0,0,0,0,0,5,0,0,0,0,0,
%T A074039 0,0,0,0,0,0,6,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,7,0,0,0,0,0,0,0,0,0,
%U A074039 0,0,8,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
%N A074039 If (n, n+2) is the k-th twin prime pair then k else 0.
%H A074039 Amiram Eldar, <a href="/A074039/b074039.txt">Table of n, a(n) for n = 1..10000</a>
%F A074039 A001359(a(n)) = n, A006512(a(n)) = n+2.
%t A074039 seq[max_] := Module[{t = Select[Range[max], And @@ PrimeQ[# + {0, 2}] &], v}, v = Table[0, {max}]; v[[t]] = Range[Length[t]]; v]; seq[100] (* _Amiram Eldar_, Apr 06 2025 *)
%Y A074039 Cf. A001359, A006512, A049084, A074038.
%K A074039 nonn
%O A074039 1,5
%A A074039 _Reinhard Zumkeller_, Aug 13 2002