G.f.: exp( Sum_{n>=1} x^n/n * exp( Sum_{k>=1} binomial(2*n*k,n*k)/2 * x^(n*k)/k ) ).
A205504
G.f.: exp( Sum_{n>=1} x^n/n * exp( Sum_{k>=1} binomial(2*n*k,n*k)/2 * x^(n*k)/k ) ).
Terms
- a(0) =1a(1) =1a(2) =2a(3) =4a(4) =11a(5) =27a(6) =92a(7) =252a(8) =906a(9) =2787a(10) =10191a(11) =31594a(12) =125998a(13) =393021a(14) =1535964a(15) =5161328a(16) =20221291a(17) =66306664a(18) =273756969a(19) =897440988a(20) =3664037417a(21) =12621555612a(22) =50496343297a(23) =170909672792a(24) =725703552284
External references
- oeis: A205504