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 A336697 #15 Aug 24 2020 22:28:36
%S A336697 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,5,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,
%T A336697 1,1,1,1,1,1,1,1,1,1,1,1,5,1,1,13,1,1,1,1,1,1,1,1,1,1,1,5,1,1,1,1,1,1,
%U A336697 1,1,1,5,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,5,1,1,1,1,1,1,1,1,1,1,1,1,1
%N A336697 a(n) = gcd((s+1)/2, 1+sigma(s)), where s is the n-th odd square, (2n-1)^2.
%C A336697 See comments in A336700, A337337, and A337339.
%H A336697 Antti Karttunen, <a href="/A336697/b336697.txt">Table of n, a(n) for n = 1..16396</a>
%H A336697 Antti Karttunen, <a href="/A336697/a336697.txt">Data supplement: n, a(n) computed for n = 1..65537</a>
%H A336697 <a href="/index/Si#SIGMAN">Index entries for sequences related to sigma(n)</a>
%F A336697 For all n >= 1, a(A048673(n)) = A337337(n).
%t A336697 Array[GCD[(# + 1)/2, 1 + DivisorSigma[1, #]] &[(2 # - 1)^2] &, 120] (* _Michael De Vlieger_, Aug 24 2020 *)
%o A336697 (PARI) A336697(n) = { my(s=((n+n-1)^2)); gcd((s+1)/2,1+sigma(s)); };
%Y A336697 Cf. A000203, A016754, A048673, A336700, A337337, A337339.
%K A336697 nonn
%O A336697 1,17
%A A336697 _Antti Karttunen_, Aug 18 2020