GFR Wrote:, and:

Wah, the second one is wrong! As Andydude wrote, the odd hyperexponentials are bounded below. The even hyper exponentials b[2n]x are not bounded below but only defined on -2n+2=-(2n-3)-1<x.

We have the general relation

b[2n]x = .

in this case:

b[6]x =

though that is probably not right either. But the true value

b[2n]x = .