a(n) = 5^(n-1/2) * (2*n-1)!! * Integral_{x = 0..1/2} 1/(1+x^2)^(n + 1/2) dx.
A090598
a(n) = 5^(n-1/2) * (2*n-1)!! * Integral_{x = 0..1/2} 1/(1+x^2)^(n + 1/2) dx.
Terms
- a(0) =1a(1) =14a(2) =328a(3) =10800a(4) =458880a(5) =23911680a(6) =1477278720a(7) =105623562240
External references
- oeis: A090598