G.f.: A(x,y) = Sum_{n=-oo..+oo} (x*y)^(n*(n+1)/2) * C(x)^n, where C(x) = 1 + x*C(x)^2 is the g.f. of the Catalan numbers (A000108), as a triangle of coefficients T(n,k) of x^n*y^k in A(x,y), read by rows n >= 0.

A355343

G.f.: A(x,y) = Sum_{n=-oo..+oo} (x*y)^(n*(n+1)/2) * C(x)^n, where C(x) = 1 + x*C(x)^2 is the g.f. of the Catalan numbers (A000108), as a triangle of coefficients T(n,k) of x^n*y^k in A(x,y), read by rows n >= 0.

Terms

    a(0) =2a(1) =-1a(2) =2a(3) =-1a(4) =-1a(5) =0a(6) =-2a(7) =1a(8) =0a(9) =2a(10) =-5a(11) =3a(12) =0a(13) =-1a(14) =0a(15) =-14a(16) =9a(17) =0a(18) =5a(19) =0a(20) =0a(21) =-42a(22) =28a(23) =0a(24) =13a(25) =0a(26) =0a(27) =2a(28) =-132a(29) =90

External references