arctanh(tan(arctanh(x))) = x + (6/3!)*x^3 + (184/5!)*x^5 + 13360/7!*x^7 + ...

A012181

arctanh(tan(arctanh(x))) = x + (6/3!)*x^3 + (184/5!)*x^5 + 13360/7!*x^7 + ...

Terms

    a(0) =1a(1) =6a(2) =184a(3) =13360a(4) =1770880a(5) =373587200a(6) =115086003200

External references