# Thread: What number comes next in the sequence:?

1. YahooHoo
Join Date
Aug 2007
Posts
1

## What number comes next in the sequence:?

61, 691, 163, 487, 4201, ?

2. YahooHoo
Join Date
Aug 2007
Posts
1
9631

the numbers are prime numbers that, when their digits are reversed, are perfect squares. Thanks for the challenge!

3. Ajm
YahooHoo
Join Date
Aug 2007
Posts
1
If you look at the sequence, you'll notice that every number is prime. Also, if you reverse each number, you get:

16,196,361,784,1024

and each of these numbers are perfect squares. So which number is prime and if reversed is a perfect square? Well to save you time the number is 9631. The reverse of that number, 1369, is a perfect square, and 9631 is prime.
So the next number in the sequence is 9361
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