G.f.: A(x,y) = Sum_{n=-oo..+oo} (x*y)^(n*(n+1)/2) * C(x)^(2*n-1), where C(x) = 1 + x*C(x)^2 is the g.f. of the Catalan numbers (A000108).
A355346
G.f.: A(x,y) = Sum_{n=-oo..+oo} (x*y)^(n*(n+1)/2) * C(x)^(2*n-1), where C(x) = 1 + x*C(x)^2 is the g.f. of the Catalan numbers (A000108).
Terms
- a(0) =2a(1) =-4a(2) =2a(3) =-1a(4) =-4a(5) =0a(6) =-3a(7) =7a(8) =0a(9) =2a(10) =-8a(11) =5a(12) =0a(13) =-4a(14) =0a(15) =-23a(16) =14a(17) =0a(18) =23a(19) =0a(20) =0a(21) =-70a(22) =41a(23) =0a(24) =21a(25) =0a(26) =0a(27) =2a(28) =-222a(29) =127
External references
- oeis: A355346