| FORMULA
|
a(n) = (2*n + 1)!/(4^n*n!^2) * hypergeom([-Sum_{k = 0..n, -1/} (2], [- ^k)*binomial(n - , k)*binomial(1/2], -1). (End), k).
a(n) = (2^n)* Sum_{k = 0..n} binomial(n, k)*binomial(k+1/2, n). See A008288.
a(n) = (2*n + 1)!/(2^n * n!^2) * hypergeom([-n, -1/2], [- n - 1/2], -1).
a(n) = 2^n * hypergeom([-n, -1/2], [1], 2).
a(n) = (-1/2)^n * binomial(2*n, n)/(1 - 2*n) * hypergeom([-n, 3/2], [-n+3/2], -1).(End)
|