MathOverflow will be down for maintenance for approximately 3 hours, starting Monday evening (06/24/2013) at approximately 9:00 PM Eastern time (UTC-4).
show/hide this revision's text 6 added 1 characters in body

I guess you can find plenty of them in the Problem Department of the American Matematical Mathematical Monthly. For instance, here is a nice one by M. Hajja and P. Walker:

Evaluate $\displaystyle \int_{0}^{1}\int_{0}^{1} \int_{0}^{1} (1+u^{2}+v^{2}+w^{2})^{-2} du dv dw $.

Good thing about this one is that there may exist a CAS out there that does not give you the answer at once.

show/hide this revision's text 5 added 4 characters in body

I guess you can find plenty of them in the Problem Department of the American Matematical Monthly. For instance, here is a nice one by M. Hajja and P. Walker:

Evaluate $\displaystyle \int_{0}^{1}\int_{0}^{1} \int_{0}^{1} (1+u^{2}+v^{2}+w^{2})^{-2} du dv dw $.

Good thing about this one is that there may exist a CAS out there that does not give you the answer at once.

show/hide this revision's text 4 added 15 characters in body

I guess you can find plenty of them in the Problem Department of the American Matematical Monthly. For instance, here is a nice one by M. Hajja and P. Walker:

Evaluate $\displaystyle \int_{0}^{1}\int_{0}^{1} \int_{0}^{1} (1+u^{2}+v^{2}+w^{2})^{-2} du dv dw $.

Good thing about this one is that there may exist a CAS out there that doe does not give the answer at once.

show/hide this revision's text 3 added 103 characters in body; edited body
show/hide this revision's text 2 added 14 characters in body
show/hide this revision's text 1