2005 base 10 is not a square. Neither is 2005 base 7 a square (equal 2*7^3+5=691). Is there any base b such that 2005 base b is a square?

(In reply to re: Solution by pcbouhid)

I agree! Yet, if:

4*b'^3 = a'^2 + a' - 1

we'd still have an even number on the left and an odd on the right, proving the impossible.

I think that's right. :D

Posted by Bruno on 2005-05-31 23:31:09