G.f.: A(x) = (1-sqrt(1-4*x))/2 o x/(1-x) o (x-x^2), a composition of functions involving the Catalan function and its inverse.
A120010
G.f.: A(x) = (1-sqrt(1-4*x))/2 o x/(1-x) o (x-x^2), a composition of functions involving the Catalan function and its inverse.
Terms
- a(0) =1a(1) =1a(2) =1a(3) =2a(4) =6a(5) =18a(6) =53a(7) =158a(8) =481a(9) =1491a(10) =4688a(11) =14913a(12) =47913a(13) =155261a(14) =506881a(15) =1665643a(16) =5504988a(17) =18287338a(18) =61027991a(19) =204499397a(20) =687808931a(21) =2321177071a(22) =7857504876a(23) =26673769002a(24) =90783820081a(25) =309720079813
External references
- oeis: A120010