a(n) = 1 + Sum_{j=1..n} Product_{k=0..j-1} binomial(2*n-1,n+k) / binomial(2*n-1,k).

A342967

a(n) = 1 + Sum_{j=1..n} Product_{k=0..j-1} binomial(2*n-1,n+k) / binomial(2*n-1,k).

Terms

    a(0) =1a(1) =2a(2) =5a(3) =22a(4) =177a(5) =2606a(6) =70226a(7) =3457742a(8) =311348897a(9) =51177188350

External references