Sum_{n >= 0} a(n) * x^n / n!^2 = exp(-2*x)/(1-x)^3.

A052127

Sum_{n >= 0} a(n) * x^n / n!^2 = exp(-2*x)/(1-x)^3.

Terms

    a(0) =1a(1) =1a(2) =8a(3) =96a(4) =2112a(5) =68160a(6) =3087360a(7) =185633280a(8) =14301020160

External references