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Old 01-24-2006, 11:28 AM
Exigency Exigency is offline
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Join Date: Jan 2006
Posts: 4
Default Re: really hard puzzle, noone has solved yet...

[ QUOTE ]
philo, if there is a puzzle that starts like this:

2 3 5 7 11 13 17 19 23 29 31 37 41 43 47 53 59


how is the next number ANYTHING BUT 61?!?!?!? this must be the only unique answer to this puzzle. if you can come up with some math or logic that will yeild a different number, please show us now.

[/ QUOTE ]

I'll give you two solutions:

Rule 1: Primes that do not include the digit 6. The next value is therefore 71.

Rule 2: Digital Clock Primes. The next number is therefore 101.

"On a 24-hour digital clock, there are 211 possible prime values: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 101, ..."

Ref: http://mathworld.wolfram.com/ClockPrime.html
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