Numerator of [x^(2n+1)] in the Taylor expansion arcsin(cosec(x) - cosech(x)) = x/3 + x^3/162 + 5*x^5/1134 + 19*x^7/76545 + 13793*x^9/218245104 + ...

A013531

Numerator of [x^(2n+1)] in the Taylor expansion arcsin(cosec(x) - cosech(x)) = x/3 + x^3/162 + 5*x^5/1134 + 19*x^7/76545 + 13793*x^9/218245104 + ...