Product_{n>=1} 1 / (1 - x^(2*n))^(a(n)/(2*n)!) = cosh(x).

A354064

Product_{n>=1} 1 / (1 - x^(2*n))^(a(n)/(2*n)!) = cosh(x).

Terms

    a(0) =1a(1) =-8a(2) =-104a(3) =1408a(4) =-354944a(5) =47546368a(6) =-6204652544a(7) =68669145088

External references