E.g.f. A(x) = F(x)^2 where F(x) is the e.g.f. of A179421.

A179423

E.g.f. A(x) = F(x)^2 where F(x) is the e.g.f. of A179421.

Terms

    a(0) =1a(1) =2a(2) =10a(3) =90a(4) =1240a(5) =23800a(6) =598788a(7) =18932620a(8) =729558240a(9) =33475442400

External references