All about flooble | fun stuff | Get a free chatterbox | Free JavaScript | Avatars    
perplexus dot info

Home > Just Math
Looking for a square result (Posted on 2018-06-14) Difficulty: 3 of 5
For each positive integer n, let Mn be the square matrix (nxn) where each diagonal entry is 2018, and every other entry is 1.

Determine the smallest positive integer n (if any) for which the value
of det(Mn) is a perfect square.

No Solution Yet Submitted by Ady TZIDON    
No Rating

Comments: ( Back to comment list | You must be logged in to post comments.)
No Subject | Comment 8 of 18 |
I think my determinant formulae are correct but I made an error coding the even one. I believe you also copied my error:

line 50 :Det=D^Xn-Xi*D+int(Xi-1)

should be 
:Det=D^Xn-Xi*D^2+int(Xi-1)

I think this makes the case n=4 a square! Do you agree? 
(Otherwise, without a solution, where did 2018 come from :-) )

Thanks for conquering the roundoff question. 

  Posted by Steven Lord on 2018-06-15 11:27:49
Please log in:
Login:
Password:
Remember me:
Sign up! | Forgot password


Search:
Search body:
Forums (0)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (2)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:
Copyright © 2002 - 2018 by Animus Pactum Consulting. All rights reserved. Privacy Information