mersenneforum.org  

Go Back   mersenneforum.org > Extra Stuff > Blogorrhea > enzocreti

Reply
 
Thread Tools
Old 2020-06-14, 08:04   #1
enzocreti
 
Mar 2018

523 Posts
Default 512

Is 512 the only cube with the property that if the digits are reversed, the reverse 215 is a cube minus one?
enzocreti is offline   Reply With Quote
Old 2020-06-14, 09:13   #2
paulunderwood
 
paulunderwood's Avatar
 
Sep 2002
Database er0rr

D4D16 Posts
Default

Quote:
Originally Posted by enzocreti View Post
Is 512 the only cube with the property that if the digits are reversed, the reverse 215 is a cube minus one?
0^3 is a cube. Reversed is 0 and that is 1 less than 1 which is also a cube: 1^3
paulunderwood is offline   Reply With Quote
Old 2020-06-14, 11:44   #3
paulunderwood
 
paulunderwood's Avatar
 
Sep 2002
Database er0rr

340510 Posts
Default

Quote:
Originally Posted by enzocreti View Post
Is 512 the only cube with the property that if the digits are reversed, the reverse 215 is a cube minus one?
If you allow for leading zeroes to removed there are infinite many solutions:

(8*10^n)^3 == 512*10^(3*n). Reversed it is 000...000215 which is 1 fewer than 6^3
paulunderwood is offline   Reply With Quote
Reply

Thread Tools


All times are UTC. The time now is 19:08.

Sat Sep 26 19:08:22 UTC 2020 up 16 days, 16:19, 1 user, load averages: 1.60, 1.64, 1.75

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.