a(n) = Sum_{k=0..n} C(2*n-2*k,n-k)^2 * C(2*n,k)^2.
A036915
a(n) = Sum_{k=0..n} C(2*n-2*k,n-k)^2 * C(2*n,k)^2.
Terms
- a(0) =1a(1) =8a(2) =136a(3) =2996a(4) =76168a(5) =2121808a(6) =62886484a(7) =1947164948a(8) =62250464648
External references
- oeis: A036915