G.f.: Sum_{n>=0} x^n*Sum_{k=0..n} (-1)^k * C(n,k)^2 * Sum_{j=0..k} C(k,j)^2 * x^j.
A245925
G.f.: Sum_{n>=0} x^n*Sum_{k=0..n} (-1)^k * C(n,k)^2 * Sum_{j=0..k} C(k,j)^2 * x^j.
Terms
- a(0) =1a(1) =-3a(2) =25a(3) =-243a(4) =2601a(5) =-29403a(6) =344569a(7) =-4141875a(8) =50737129a(9) =-630663003a(10) =7930793025a(11) =-100681224075
External references
- oeis: A245925