 Bug: Attempting to calculate a double sum crashes the CAS - Printable Version +- HP Forums (https://www.hpmuseum.org/forum) +-- Forum: HP Calculators (and very old HP Computers) (/forum-3.html) +--- Forum: HP Prime (/forum-5.html) +--- Thread: Bug: Attempting to calculate a double sum crashes the CAS (/thread-5292.html) Bug: Attempting to calculate a double sum crashes the CAS - quinyu - 12-07-2015 10:06 PM Calculating the following double sum causes a calculator crash: [attachment=2931] While I understand that the closed form is nasty (involves the Psi function, plus the Euler-Mascheroni constant), the Prime could just say "no idea" instead of crashing. (Solution from Wolfram Alpha. TI nSpire CAS just returns the expression.) [attachment=2932] This is Software Version 2015 6 17 (8151), HW ver C, CAS version 1.1.2-11, OS 0.037.526 RE: Bug: Attempting to calculate a double sum crashes the CAS - quinyu - 12-07-2015 10:42 PM HP 50g delivers a half-solution, giving [attachment=2933] RE: Bug: Attempting to calculate a double sum crashes the CAS - DrD - 12-07-2015 10:54 PM Does this work on Wolfram, Matlab, et al? RE: Bug: Attempting to calculate a double sum crashes the CAS - quinyu - 12-07-2015 11:42 PM Wolfram Alpha gives identical result. (Sorry, earlier I thought that Mathematica would too - no, see below.) Maple 18 gives: [attachment=2934] (some little editing to keep style consistent, and factor things a little) MuPAD gives the same half-solution as the HP 50g. Matlab R2015a also. RE: Bug: Attempting to calculate a double sum crashes the CAS - quinyu - 12-08-2015 07:41 AM Best sum that I could find with Mathematica 10.0 is: [attachment=2935], where H_n is the nth harmonic number. This is the one I like the most, so far.