a(n) = Sum_{k=0..n} (-1)^(n-k) * (binomial(n,k) * binomial(n+k,k))^2.

A382849

a(n) = Sum_{k=0..n} (-1)^(n-k) * (binomial(n,k) * binomial(n+k,k))^2.

Terms

    a(0) =1a(1) =3a(2) =1a(3) =-357a(4) =-6999a(5) =-62997a(6) =444529a(7) =27783003a(8) =508019689a(9) =3206511003a(10) =-89889084999

External references