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 A003444 M3455 #34 Nov 29 2023 06:58:37
%S A003444 1,4,12,43,143,504,1768,6310,22610,81752,297160,1086601,3991995,
%T A003444 14732720,54587280,202997670,757398510,2834510744,10637507400,
%U A003444 40023636310,150946230006,570534578704,2160865067312,8199711378716,31170212479588,118686578956272
%N A003444 Number of dissections of a polygon.
%C A003444 See A220881 for an essentially identical sequence, but with a different offset and a more precise definition. - _N. J. A. Sloane_, Dec 28 2012
%C A003444 Also number of necklaces of 2 colors with 2n beads and n-2 black ones. - _Wouter Meeussen_, Aug 03 2002
%D A003444 P. Lisonek, Closed forms for the number of polygon dissections. Journal of Symbolic Computation 20 (1995), 595-601.
%D A003444 R. C. Read, On general dissections of a polygon, Aequat. Math. 18 (1978), 370-388.
%D A003444 N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).
%H A003444 T. D. Noe, <a href="/A003444/b003444.txt">Table of n, a(n) for n = 4..201</a>
%H A003444 D. Bowman and A. Regev, <a href="http://arxiv.org/abs/1209.6270">Counting symmetry classes of dissections of a convex regular polygon</a>, arXiv:1209.6270 [math.CO], 2012.
%F A003444 a(n) = (1/(2n)) Sum_{d |(2n, k)} phi(d)*binomial(2n/d, k/d) with k=n-2. - _Wouter Meeussen_, Aug 03 2002
%t A003444 Table[(Plus@@(EulerPhi[ # ]Binomial[2n/#, (n-2)/# ] &)/@Intersection[Divisors[2n], Divisors[n-2]])/(2n), {n, 3, 32}]
%Y A003444 Cf. A003445, A003450, A047996, A073020, A220881.
%K A003444 nonn
%O A003444 4,2
%A A003444 _N. J. A. Sloane_
%E A003444 More terms from _Wouter Meeussen_, Aug 03 2002