G.f.: exp(Sum_{k>=1} B(x^k)/k), where B(x) = x + 2*x^2 + 5*x^3 + 14*x^4 + 42*x^5 + ... = (C(x)-1)/x and C is the g.f. for the Catalan numbers A000108.
A088327
G.f.: exp(Sum_{k>=1} B(x^k)/k), where B(x) = x + 2*x^2 + 5*x^3 + 14*x^4 + 42*x^5 + ... = (C(x)-1)/x and C is the g.f. for the Catalan numbers A000108.
Terms
- a(0) =1a(1) =1a(2) =3a(3) =8a(4) =25a(5) =77a(6) =256a(7) =854a(8) =2940a(9) =10229a(10) =36124a(11) =128745a(12) =463137a(13) =1677816a(14) =6118165a(15) =22432778a(16) =82660369a(17) =305916561a(18) =1136621136a(19) =4238006039a(20) =15852603939a(21) =59471304434a(22) =223704813807a(23) =843547443903
External references
- oeis: A088327