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 A107427 #5 Mar 31 2012 21:08:36 %S A107427 0,0,1,2,4,7,10,14,18,22 %N A107427 Maximal number of simple triangular regions that can be formed by drawing n line segments in the Euclidean plane. %C A107427 Draw n line segments on a piece of paper in such a way that if we make cuts along those lines, only triangular pieces are formed (apart from the "outside" region). Sequence gives maximal number of triangles that can be obtained. %C A107427 Inspection of Loy's web page shows that these are known to be optimal only for n up to about 7. %C A107427 Loy gives the following lower bounds for n = 1, 2, 3, ...: 0, 0, 1, 2, 4, 7, 10, 14, 18, 22, 27, 32, 38, 44, 50, 54, 60, 72, 76, 84, 92, 110, 114, 122, 130, 156, 160, 210 %H A107427 David Coles, <a href="http://davcoles.tripod.com">Triangle Puzzle</a>. %H A107427 Jim Loy, <a href="http://www.jimloy.com/puzz/cole.htm">Triangle Puzzle</a>. %H A107427 Jim Loy, <a href="/A107427/a107427.gif">Illustration of a(6) = 7</a> %e A107427 7 lines can make at most 10 triangles, so a(7) = 10. %Y A107427 Cf. A000124. %K A107427 nonn,nice,more %O A107427 1,4 %A A107427 _Bill Blewett_, May 22 2005 %E A107427 Entry revised by _N. J. A. Sloane_, May 29 2005