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 A156106 #15 Nov 30 2022 10:02:33 %S A156106 1,3,15,99,783,6987,67671,694035,7418943,81800091,923720679, %T A156106 10630297827,124224709455,1470172954347,17585028636279, %U A156106 212248303720371,2581823992868703 %N A156106 Expansion of F(1/3,2/3;1/2;27*x/2) / F(1/3,-1/3;-1/2;27*x/2). %C A156106 Hankel transform is 3^n*2^(n^2)*A005156 = 6^n*4^C(n,2)*A005156 = 3^n*A002416*A005156. %H A156106 I. Gessel and G. Xin, <a href="https://arxiv.org/abs/math/0505217">The Generating Function of Ternary Trees and Continued Fractions</a>, arXiv:math/0505217 [math.CO], 2005. %F A156106 D-finite with recurrence: 2*(2*n-1)*(n-2)*a(n) + (-72*(n-3)^2-171*n+420)*a(n-1) + (297*(n-3)^2+675*n-1674)*a(n-2) - 81*(3*n-5)*(3*n-7)*a(n-3) = 0. - _Georg Fischer_, Nov 30 2022 %K A156106 easy,nonn %O A156106 0,2 %A A156106 _Paul Barry_, Feb 04 2009