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 A192631 #11 Sep 07 2013 14:30:48 %S A192631 1,33,17,105,549120 %N A192631 Numerators of the Diophantus-Dujella rational Diophantine quintuple: 1 + the product of any two distinct terms is a square. %C A192631 Denominators are A192632. Diophantus found the rational Diophantine quadruple 1/16, 33/16, 17/4, 105/16. Dujella added a fifth rational number 549120/10201. %C A192631 It is unknown whether this rational Diophantine quintuple can be extended to a sextuple. Herrmann, Pethoe, and Zimmer proved that the sequence is finite, but no bound on its length is known. %C A192631 See A030063 for additional comments, references, and links. %D A192631 E. Herrmann, A. Pethoe and H. G. Zimmer, On Fermat's quadruple equations, Abh. Math. Sem. Univ. Hamburg 69 (1999), 283-291. %H A192631 A. Dujella, <a href="http://web.math.hr/~duje/ratio.html">Rational Diophantine m-tuples</a> %e A192631 1/16, 33/16, 17/4, 105/16, 549120/10201. %e A192631 1 + (1/16)*(33/16) = (17/16)^2. %e A192631 1 + (33/16)*(549120/10201) = (1069/101)^2. %Y A192631 Cf. A030063, A192629, A192630, A192632. %K A192631 nonn,fini,frac %O A192631 1,2 %A A192631 _Jonathan Sondow_, Jul 07 2011