a(n) = Product_{1<=j,k<=n} (4*sin(Pi*(4*j-1)/(4*n))^2 + 4*sin(Pi*(2*k-1)/(2*n))^2).
A340557
a(n) = Product_{1<=j,k<=n} (4*sin(Pi*(4*j-1)/(4*n))^2 + 4*sin(Pi*(2*k-1)/(2*n))^2).
Terms
- a(0) =1a(1) =6a(2) =196a(3) =64152a(4) =220581904
External references
- oeis: A340557