perplexus.info :: Numbers : 3 and 4-digit numbers

3 and 4-digit numbers (Posted on 2017-07-17)

Consider the number 4808
Notice: 4^2+8^2=80
i.e. the sum of the squares of this number's first and last digits equals the number obtained when the first and last digits are erased.

How many numbers with such feature exist below 10000?

Clearly, no leading zeroes.

Submitted by Ady TZIDON

No Rating

Solution: (Hide)

There are 83 numbers that qualify (see detailed answers by solvers).

Comments: ( You must be logged in to post comments.)

Subject	Author	Date
Puzzle Answer	K Sengupta	2022-07-27 23:36:55
re(4): Just counting (spoiler)	Steve Herman	2017-07-18 09:08:51
re(3): Just counting (spoiler)	Charlie	2017-07-17 21:59:59
re(3): Just counting (spoiler)	Ady TZIDON	2017-07-17 14:16:13
re(2): Just counting (spoiler)	Steve Herman	2017-07-17 13:59:08
re: Just counting (spoiler)	Charlie	2017-07-17 13:53:40
Just counting (spoiler)	Steve Herman	2017-07-17 13:08:18

Please log in:

Login:
Password:
Remember me:

Sign up! \| Forgot password

Search:

Search body:

Forums (1)
Newest Problems
Random Problem
FAQ | About This Site
Site Statistics
New Comments (6)
Unsolved Problems
Top Rated Problems
This month's top
Most Commented On

Chatterbox:


perplexus dot info