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 A123472 #33 Aug 04 2025 01:02:59 %S A123472 1,2,4,11,33,146,886,8483,126029,2866876,95717334,4534590984 %N A123472 Number of weakly triangulated simple graphs on n unlabeled nodes. %C A123472 All weakly triangulated graphs are perfect. %C A123472 Also known as weakly chordal graphs. This sequence counts both connected and disconnected graphs. - _Jim Nastos_, Jul 23 2025 %H A123472 S. Hougardy, <a href="http://www.or.uni-bonn.de/~hougardy/">Home Page</a> %H A123472 S. Hougardy, <a href="http://dx.doi.org/10.1016/j.disc.2006.05.021">Classes of perfect graphs</a>, Discr. Math. 306 (2006), 2529-2571. %F A123472 Euler transform of A079457. - _Falk Hüffner_, Jan 15 2016 %o A123472 (Sage) %o A123472 for n in range(1, 11): %o A123472 count = 0 %o A123472 for G in graphs(n): %o A123472 if G.is_weakly_chordal(): %o A123472 count += 1 %o A123472 print(n, count) %o A123472 # _Jim Nastos_, Jul 25 2025 %K A123472 nonn,more %O A123472 1,2 %A A123472 _N. J. A. Sloane_, Oct 18 2006 %E A123472 a(10) and a(11) added using formula by _Falk Hüffner_, Jan 15 2016 %E A123472 Name clarified by _Jim Nastos_, Jul 23 2025