47546368domain: NAppears in sequencesProduct_{n>=1} 1 / (1 - x^(2*n))^(a(n)/(2*n)!) = cosh(x).at n=5A354064Product_{n>=1} (1 + x^(2*n))^(a(n)/(2*n)!) = cos(x).at n=5A354173