RE: Derivatives of the Riemann xi function at s=1/2

[Jacques Gélinas <jacquesg00@hotmail.com>]

Sorry, the first paragraph with the Pari/GP related question got lost in my previous post.

When using the integral representation of the derivatives of the xi(s) function,
an overflow occurs in the (double) exponential function, 
  *** exp: overflow in expo().
and the clumsy cut-off below must be used. 

xik (k,m=12) = intnum( t=0, [[1],1],  2 * Mt(exp(2*t),m) * t^k );
Mt  (x,m=12) = 4 * x^(5/4) * sum(k=1, m, k^2*Pi * (k^2*Pi*x - 3/2) * eexp(-k^2*Pi*x) );
eexp(x) = if( x < -178482300, 0, exp(x) );

Is there a better solution to this overflow (in fact underflow) problem ?

(The rest of the previous post is less important, and can be ignored).

Jacques Gélinas, Ottawa