128750

Appears in sequences

• G.f.: (1-2*x*c(x))/(1-3*x*c(x)) where c(x) = (1 - sqrt(1-4*x))/(2*x) is the g.f. for Catalan numbers A000108.at n=9A049027
• Square array read by antidiagonals: T(n,k)=(T(n,k-1)*n^2-Catalan(k-1))/(n-1) with a(n,1)=1 and a(1,k)=Catalan(k) where Catalan(k)=C(2k,k)/(k+1)=A000108(k).at n=57A067345
• Riordan array (1/(1-3x*c(x)),xc(x)), c(x) the g.f. of A000108.at n=46A117375
• Expansion of Product_{n>=1} (1 - x^(5*n))/(1 - x^n)^3 in powers of x.at n=18A278668
• Array read by downward antidiagonals: A(n,k) = A(n-1,k+1) + Sum_{j=0..k} A(n-1,j)*A(k-j,0) with A(0,k) = 1.at n=41A392095