G.f.: 1/(1-x) = Sum_{n>=0} a(n) * x^n / Product_{k=1..2*n-1} (1 + k*x).

A208830

G.f.: 1/(1-x) = Sum_{n>=0} a(n) * x^n / Product_{k=1..2*n-1} (1 + k*x).

Terms

    a(0) =1a(1) =1a(2) =2a(3) =12a(4) =132a(5) =2196a(6) =49836a(7) =1447476a(8) =51542868a(9) =2182001316a(10) =107319488412

External references