Скачать с ютуб A number theory adventure - JBMO 2002 - P3 в хорошем качестве

A number theory adventure - JBMO 2002 - P3

TIMESTAMPS 00:00 Who this problem is for 00:35 25 - 45/75 - 150 Take 5 minutes 00:55 Trying to understand the problem 01:16 First thing we notice about n 01:55 Second thing we notice about d_5 02:55 What do the number of divisors tell us about n 06:30 Trying to look at how other numbers force d_5 to be something 09:40 Looking at an idea with size 10:30 Looking at d_3 and some casework to explore the problem 16:20 Bringing together the ideas from our exploration of cases 20:40 Reiterating ideas thus far 22:07 Looking at what d_4 can be 24:55 Looking at what d_5 can be now 28:00 Seeing what form n can take 32:00 The form n needs to take 32:30 Someone forgets about parity 34:06 Looking at q + 2 36:00 Looking at what bounds on d_5 give us 37:20 Looking at consecutive primes and how they constrain what n's prime factors can be 38:30 Case where d_5 isn't r 39:20 Case where q, r = 5, 7 40:08 Case where q, r = 11, 13 42:38 Reflecting on the problem 43:03 Thanks for problem solving :)