# What comes next?5, 3, 42, 86, 15, 24, 25, 168, 2, 4, ?

What comes next?

5, 3, 42, 86, 15, 24, 25, 168, 2, 4, ?

6 could it be

Nope, not 6.

Larger.

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Good job, Bicycle Tree! You're good.

James R
Homework Helper
Gold Member
Is anybody going to explain?

Ok. The sequence is a palindrome.

In that case, 3 would serve as well (until moo added the extra condition).

what palindrome suppose to mean ?

Man... darn... I saw it right after I looked at BicycleTree's response... Oh well.

ArielGenesis said:
what palindrome suppose to mean ?

Palindrome is the same backwards as it is forwards... they just have the commas in strange places.

NateTG
Homework Helper
But there's an infinite number of options that makes it a palindrome. For example:
42861524251682435
142861524251682435
1142861524251682435
11142861524251682435
111142861524251682435
1111142861524251682435

And so on.

If you take the 4 (from the 24) as the middle of the sequence, then the numbers before and after are the same. So directly before/after the 4 there is a 2 then a 5 then a 1 then a 6 and then an 8 and so on. I would have thought that the answer could have also been:
'3, 5' (but then there would be more commas on the right of the 4)

PS

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so the trick is just right at the comma. i got it. thx all