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What will be next term of given series:

$$​50, 30, 40, 75, 170, ?$$

I am not able to find the pattern in the series. Could someone help me with this?

Stefan Perko
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MathGeek
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    Could be anything you wish. – jim Jul 15 '16 at 16:49
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    http://math.stackexchange.com/questions/1790642/general-formula-for-the-1-5-19-65-211-sequence – Jack D'Aurizio Jul 15 '16 at 16:51
  • See question 5 here: http://emahendras.org/downlods/Digi-Page-22-06-2016-Reasoning-English.pdf Apparently the answer is 450. – smcc Jul 15 '16 at 16:53
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    @jim I am glad to see that someone agrees with me that "the guessing of the next term from a finite number of samples" is an unfair game . – Mick Jul 15 '16 at 16:53
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    @jim I believe pattern recognition is on topic on MSE, if there exists a tag for it. So I hardly think this is a valid response. Of course the OP could try to provide more context. – Stefan Perko Jul 15 '16 at 16:53
  • @smcc holy cow, those are all really difficult – Asinomás Jul 15 '16 at 16:55
  • Not so difficult when the answer is given with the questions – smcc Jul 15 '16 at 16:55
  • Well yeah, but even with the answers I have no idea what the reasoning is – Asinomás Jul 15 '16 at 16:57
  • For example. problem $2$ the sequence is $1\times11, 2\times 11, 4\times 11, 7\times 11,11\times 11$. OEIS can find $170$ sequences starting with $1,2,4,7,11,$ and only $54$ of these predict the next term "correctly" – Asinomás Jul 15 '16 at 17:00

1 Answers1

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$$x_1=50$$ $$x_{n+1}=n\left(\frac{x_n}{2}+5\right)$$

My python code to verify it.

Siong Thye Goh
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