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

A354174

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

Terms

    a(0) =1a(1) =4a(2) =-104a(3) =8128a(4) =-354944a(5) =-21642752a(6) =-6204652544

External references