Sum_{k=0..n} C(n,k)^4*C(n+k,k)^2.
A218690
Sum_{k=0..n} C(n,k)^4*C(n+k,k)^2.
Terms
- a(0) =1a(1) =5a(2) =181a(3) =9797a(4) =616501a(5) =45778505a(6) =3678753205a(7) =314352091205
External references
- oeis: A218690
A218690
Sum_{k=0..n} C(n,k)^4*C(n+k,k)^2.