Product_{n>=1} 1 / (1 - x^n)^(a(n)/n!) = 1 + arctan(x).

A354117

Product_{n>=1} 1 / (1 - x^n)^(a(n)/n!) = 1 + arctan(x).

Terms

    a(0) =1a(1) =-2a(2) =-2a(3) =8a(4) =-16a(5) =176a(6) =-832a(7) =384a(8) =8192a(9) =447744a(10) =-4228608a(11) =-15860736a(12) =-398991360a(13) =10938421248a(14) =44581613568a(15) =-29064658944

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