Math contest #7 Results and Solution

Solution:

The problem of the last contest was:
Find the nth prime and sum up all integers between and including 1 and the prime.
Finding the nth prime is the hardest part of this. You could do this by hand by writing down a few hundred numbers and checking manually for primes, or just use a computer program.

A formula for the sum(Σ) can be easily derived, by adding the sum and the reverse ordered sum:

Σ = 1 +  2  + … +(n-1)+ n
Σ = n +(n-1)+ … +  2  + 1

↓
Σ+Σ = n+1 + n+1 + … + n+1 + n+1 = n*(n+1)
↓
Σ = n*(n+1)/2

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How your chance of winning is calculated:

• Every participant gets 1 point for entering the contest.
• Every solution entered gets 1 additional point.
• Multiple examples of a general solution count as one solution
• If there is only one general solution, those who found its pattern(by mentioning a general formula or showing more then 3 examples) will get an additional point.
• Your winning chance is "your points"/"total points"

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All participants did great and got the maximum score, but I list the score anyway.

List of participants with their scores and chance of winning, sorted by time of entry:

Name	solutions found	score	chance of winning
@heraclio	prime and sum	3	25%
@syalla	prime and sum	3	25%
@tonimontana	prime and sum	3	25%
@athunderstruck	prime and sum	3	25%

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(Double) Winner draw(using a self written program):

Congratulations @athunderstruck and @tonimontana, you won 1 SBI each:
Hmm… I don't know away to send it to you now. I'll do the transfer as soon as steemit is working again.
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The next contest starts tomorrow(if the the blockchain stays operational until then). Don't miss it!