Numerator of (binomial(2*n-2,n-1)/n!)^2.

Terms

a(0) =1a(1) =1a(2) =1a(3) =25a(4) =49a(5) =49a(6) =121a(7) =20449a(8) =20449a(9) =5909761a(10) =17631601a(11) =17631601a(12) =55190041a(13) =55190041a(14) =55190041a(15) =46414824481a(16) =154341336769a(17) =154341336769a(18) =427538329a(19) =585299972401a(20) =585299972401