a(n) = n!^2 times coefficient of x^n in Sum_{k>=0} x^k/k!^2/4^k*((2-x)/(1-x))^(2*k).

A073179

a(n) = n!^2 times coefficient of x^n in Sum_{k>=0} x^k/k!^2/4^k*((2-x)/(1-x))^(2*k).

Terms

    a(0) =1a(1) =1a(2) =5a(3) =64a(4) =1417a(5) =47801a(6) =2278981a(7) =145735360a(8) =12026529089

External references