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 A197223 #10 Mar 30 2012 17:23:02 %S A197223 1,2,3,17,20,117,254,371,1367,15408,47591,62999,299587,2759282, %T A197223 3058869,21112496,24171365,93626591,305051138,398677729,1899762054, %U A197223 4198201837,6097963891,10296165728,36986461075,47282626803,178834341484,762619992739,941454334223 %N A197223 Denominator of convergents to e - 1/e. %t A197223 Denominator[Convergents[E - 1/E, 40]] %Y A197223 Cf. A174548 (decimal), A197222 (numerators). %K A197223 nonn %O A197223 1,2 %A A197223 _T. D. Noe_, Oct 12 2011