G.f.: exp( Sum_{n>=1} C(2*n^2,n^2) * x^n/n ).A201556G.f.: exp( Sum_{n>=1} C(2*n^2,n^2) * x^n/n ).Terms a(0) =1a(1) =2a(2) =37a(3) =16278a(4) =150303194External referencesoeis: A201556