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

A354063

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

Terms

    a(0) =-1a(1) =4a(2) =104a(3) =1408a(4) =354944a(5) =-21642752a(6) =6204652544a(7) =68669145088

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