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 A060049 #20 Jan 02 2015 21:12:23 %S A060049 1,0,1,1,2,5,15,50,181,697,2821,11892,51874,232974,1073070,5053029, %T A060049 24264565,118570292,588567257,2963358162,15114174106,78004013763, %U A060049 406971280545,2144659072330,11407141925639,61197287846831 %N A060049 Triangulations of an n-gon such that each internal vertex has valence at least 6, i.e., nonpositively curved triangulations. %C A060049 This is the connected version of A059710 in the following sense. Let C(x) be the ordinary generating function for this sequence and A(x) the ordinary generating function for A059710. Then these satisfy the functional equation A(x) = C(x*A(x)). - _Bruce Westbury_, Nov 05 2013 %H A060049 Bruce Westbury, <a href="/A060049/b060049.txt">Table of n, a(n) for n = 0..39</a> %H A060049 Greg Kuperberg, <a href="http://arxiv.org/abs/q-alg/9712003">Spiders for rank 2 Lie algebras</a>, arXiv:q-alg/9712003, 1997. %H A060049 Greg Kuperberg, <a href="http://projecteuclid.org/euclid.cmp/1104287237">Spiders for rank 2 Lie algebras</a>, Comm. Math. Phys. 180 (1996), 109-151. %H A060049 Bruce W. Westbury, <a href="http://arxiv.org/abs/math/0507112">Enumeration of non-positive planar trivalent graphs</a>, arXiv:math/0507112 [math.CO], 2005. %H A060049 Bruce W. Westbury, <a href="http://dx.doi.org/10.1007/s10801-006-0041-4">Enumeration of non-positive planar trivalent graphs</a>, J. Algebraic Combin. 25 (2007) %F A060049 The g.f. B(x) is derived from the g.f. A(x) of A059710 by A(x) = A(x*B(x))+1. %e A060049 a(6) = 15 because there are 14 = A000108(4) triangulations without internal vertices, plus the triangulation with 6 pie slices. %Y A060049 Cf. A059710. %K A060049 easy,nonn %O A060049 0,5 %A A060049 _Greg Kuperberg_, Feb 15 2001