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 A334142 #21 Feb 16 2025 08:34:00
%S A334142 2,3,4,5,6,7,8,10,11,13,14,17,18,20,21,26,27,28,29,33,34,35,36,41,42,
%T A334142 43,44,45,46,49,50,52,53,57,58,60,61,64,65,69,70,81,82,83,84,89,90,98,
%U A334142 99,104,105,109,110,113,114,116,117,120,121,140,141,142,143,144,145,148,149
%N A334142 Indices of twin primes.
%H A334142 Amiram Eldar, <a href="/A334142/b334142.txt">Table of n, a(n) for n = 1..10000</a>
%H A334142 Eric Weisstein's World of Mathematics, <a href="https://mathworld.wolfram.com/TwinPrimes.html">Twin Primes</a>.
%F A334142 a(n) = A000720(A001097(n)).
%F A334142 Set union of A029707 and A107770.
%p A334142 q:= n-> (p-> isprime(p-2) or isprime(p+2))(ithprime(n)):
%p A334142 select(q, [$1..150])[]; # _Alois P. Heinz_, Apr 15 2020
%t A334142 With[{p = PositionIndex[(#[[2]] - #[[1]] - 2) & /@ Partition[Prime[Range[150]], 2, 1]][0]}, Union[p, p + 1]] (* _Amiram Eldar_, Sep 06 2024 *)
%Y A334142 Cf. A000720, A001097, A029707, A107770.
%K A334142 nonn
%O A334142 1,1
%A A334142 _Ilya Gutkovskiy_, Apr 15 2020