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

A353928

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

Terms

    a(0) =1a(1) =-2a(2) =2a(3) =-32a(4) =64a(5) =-464a(6) =3968a(7) =-92672a(8) =414720a(9) =-5486592a(10) =68247552a(11) =-869895168a(12) =15949529088a(13) =-299609505792

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