G.f.: exp( Sum_{n>=1} binomial(2*n,n)^2 * x^n/n ).

A224734

G.f.: exp( Sum_{n>=1} binomial(2*n,n)^2 * x^n/n ).

Terms

    a(0) =1a(1) =4a(2) =26a(3) =216a(4) =2075a(5) =21916a(6) =247326a(7) =2930216a(8) =36028117a(9) =456089076a(10) =5910983050a(11) =78100285784

External references