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 A064342 #8 Aug 09 2017 12:29:28 %S A064342 1,1,8,176,5888,238848,10770432,518909952,26156466176,1362414338048, %T A064342 72751723839488,3961437637574656,219123329636761600, %U A064342 12278352550322765824,695492547259800748032,39759203500044029263872 %N A064342 Generalized Catalan numbers C(4,4; n). %C A064342 See triangle A064879 with columns m built from C(m,m; n), m >= 0, also for Derrida et al. and Liggett references. %H A064342 J. Abate, W. Whitt, <a href="https://cs.uwaterloo.ca/journals/JIS/VOL14/Whitt/whitt6.html">Brownian Motion and the Generalized Catalan Numbers</a>, J. Int. Seq. 14 (2011) # 11.2.6, corollary 6. %F A064342 a(n)= ((16^(n-1))/(n-1))*sum((m+1)*(m+2)*binomial(2*(n-2)-m, n-2-m)*((1/4)^(m+1)), m=0..n-2), n >= 2, a(0) := 1=: a(1). %F A064342 G.f.:(1-7*x*c(16*x))/(1-4*x*c(16*x))^2 = c(16*x)*(7+9*c(16*x))/(1+3*c(16*x))^2 = (7*c(16*x)*(4*x)^2+3*(3+11*x))/(3+4*x)^2 with c(x)= A(x) g.f. of Catalan numbers A000108. %F A064342 3*(-n+1)*a(n) +4*(47*n-120)*a(n-1) +128*(2*n-3)*a(n-2)=0. - _R. J. Mathar_, Aug 09 2017 %Y A064342 A064341. %K A064342 nonn,easy %O A064342 0,3 %A A064342 _Wolfdieter Lang_, Oct 12 2001