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 A023592 #15 Mar 05 2020 03:24:34
%S A023592 5,7,11,3,23,3,5,3,47,59,3,3,83,3,5,107,7,3,3,11,3,3,167,179,3,7,3,5,
%T A023592 3,227,3,263,5,3,13,3,3,3,5,347,359,3,383,3,5,3,3,3,5,3,467,479,3,503,
%U A023592 5,17,7,3,3,563,3,587,3,7,3,5,3,3,5,3,7,719,3,3,3,13,19,3,11,3
%N A023592 Least odd prime divisor of 2*prime(n)+1.
%H A023592 Amiram Eldar, <a href="/A023592/b023592.txt">Table of n, a(n) for n = 1..10000</a>
%t A023592 Table[FactorInteger[2*Prime[n] + 1][[1, 1]], {n, 1, 80}] (* _Amiram Eldar_, Mar 05 2020 *)
%o A023592 (PARI) a(n) = factor(2*prime(n)+1)[1, 1]; \\ _Michel Marcus_, Oct 02 2013
%Y A023592 Except for first term, same as A094460.
%K A023592 nonn
%O A023592 1,1
%A A023592 _Clark Kimberling_