Why can't this limit be calculated?

[Mjx121418]

limit(harmonic_number(n)/n,n=+oo)

I think it is obvious that this limit should be 0, but why can't sage solve it?

[kcrisman]

Harmonic number is probably not implemented in Maxima?  However, Sympy can do at least some limits with it - see http://docs.sympy.org/dev/modules/functions/combinatorial.html#harmonic 

[kcrisman]

And it apparently can do this one, so  indeed

http://sagecell.sagemath.org/?z=eJwrSyzSUM9T1-TlysnMzSzRyEgsys3Py0yOzyvNTUot0sjT1M_TybPVzs_XScxJzy_KLMnItVUvrswtqFTXBAB-1RUT&lang=sage

var('n')

limit(harmonic_number(n)/n,n=+oo,algorithm='sympy')

returns zero.  See https://trac.sagemath.org/ticket/22700 for a related ticket.

[Mjx121418]

Thanks a lot 🤗

在 2017年3月29日星期三 UTC+8上午1:49:39，kcrisman写道：