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

 A Composite Determination Problem (Posted on 2006-04-23)
Determine whether or not N is a composite number, where

N = 675*2621 + 677*2610 - 1

NOTE:
A prime number (or a prime) is a natural number that has exactly two (distinct) natural number divisors, which are 1 and the prime number itself. A composite number is a positive integer which has a positive divisor other than one or itself. By definition, every integer greater than one is either a prime number or a composite number. The numbers 0 and 1 are considered to be neither prime nor composite.

 See The Solution Submitted by K Sengupta Rating: 4.3333 (3 votes)

Comments: ( Back to comment list | You must be logged in to post comments.)
 A first stab at the solution | Comment 5 of 14 |
Since 26²=676, we have N=
(262-1)2621+ (262+1)2610-1=
2623-2621+2612+2610-1.

And for now, that's as far as I got... I tried mod 3, mod 5, mod 7, but it didn't work.

 Posted by e.g. on 2006-04-23 12:10:50

 Search: Search body:
Forums (0)