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 A139699 #5 Nov 11 2019 09:23:37 %S A139699 1,5,3,22,10,186 %N A139699 Positive integers x,y such that prime(x)*prime(x+y) = y^2 + 1, ordered by increasing x+y. %H A139699 Sebastian Martin Ruiz, <a href="https://web.archive.org/web/20130727093926/http://perso.wanadoo.es/smaranda/">Home Page</a> %e A139699 prime(1)*prime(1+5) = 2*13 = 26 = 5^2+1. %K A139699 nonn,tabf,more %O A139699 1,2 %A A139699 Sebastian Martin-Ruiz (s_m_ruiz(AT)yahoo.es), Aug 25 2008