165636900

Appears in sequences

• a(n) = binomial(2n, n)^2.at n=8A002894
• a(n) = binomial(n, floor(n/2))^2 = A001405(n)^2.at n=16A018224
• Expansion of (1+4x)/AGM(1+4x,1-4x) where AGM denotes the arithmetic-geometric mean.at n=16A092266
• Norm of coefficients in g.f. C(x) that satisfies: C(x) = 1 + x/C(I*x).at n=34A193384
• a(n) = binomial(n,floor(n/2))*binomial(n+1,floor(n/2+1/2))*(1+floor(n/2))/(1+2*floor(n/2)).at n=16A241530
• Triangle read by rows: T(n, k) = (binomial(n,k)*binomial(n+k,k))^2 = A063007(n, k)^2, for n >= 0, k = 0..n.at n=44A303987
• a(n) = (n!/floor(n/2)!^2)^2.at n=16A327998
• Square array read by ascending antidiagonals: T(n,k) = (2*k)!/k!^2 * ( (2*n*k)! * ((n + 2)*k)! )/( (n*k)! * ((n + 1)*k)!^2 ) for n, k > = 0.at n=44A364509