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 A180172 #11 Mar 12 2023 04:08:15
%S A180172 1,1,1,1,1,3,1,1,1,1,11,3,1,1,1,1,1,9,1,1,3,1,1,1,1,1,3,1,1,5,1,1,1,1,
%T A180172 1,9,1,1,13,5,1,3,1,1,1,1,1,3,1,1,1,1,1,1,1,1,1,1,1,1,1,1,3,1,5,11,1,
%U A180172 1,1,1,71,1,1,1,3,1,1,3,1,1,1,1,1,3,1,1,1,1,1,15,7,1,3,1,1,1,1,1,3,1,1,1,1
%N A180172 a(n) = gcd(prime(n)+2, n).
%H A180172 G. C. Greubel, <a href="/A180172/b180172.txt">Table of n, a(n) for n = 1..10000</a>
%t A180172 Table[GCD[n,Prime[n]+2],{n,200}]
%o A180172 (Magma) [GCD(n,NthPrime(n) +2): n in [1..110]]; // _G. C. Greubel_, Mar 12 2023
%o A180172 (SageMath) [gcd(nth_prime(n) + 2, n) for n in range(1,111)] # _G. C. Greubel_, Mar 12 2023
%Y A180172 Cf. A003989, A052147, A084309, A084310, A180173.
%K A180172 nonn
%O A180172 1,6
%A A180172 _Zak Seidov_, Aug 15 2010