Guest Posted June 3, 2008 Report Share Posted June 3, 2008 Find the next number in the pattern. Easy 17, 18, 20, 23, 28, 35, ? Medium 0, 1, 8, 38, 403, ? Hard (let's see how long it will take you...) -4, -3.875, 11,875, 103, 2056.125, 16762.25, ? If you find that you can't arrive at an answer: 1. Your not good enough at math. or 2. I made a mistake in my math or there is some sort of typo. Good luck! Quote Link to comment Share on other sites More sharing options...

0 Guest Posted June 5, 2008 Report Share Posted June 5, 2008 Lol, there's no logic for the stuff I do xD. I jut do it and hope it's right :X I see Well I guess trial and error can work some times. Quote Link to comment Share on other sites More sharing options...

0 Guest Posted June 6, 2008 Report Share Posted June 6, 2008 Will all next numbers in your sequence match to the numbers calculated by my suggested formula? If there is a difference, could you please tell where? Quote Link to comment Share on other sites More sharing options...

0 Guest Posted June 6, 2008 Report Share Posted June 6, 2008 Will all next numbers in your sequence match to the numbers calculated by my suggested formula? If there is a difference, could you please tell where? The number sequence is correct, your just not using the formula I want, but you are close. Quote Link to comment Share on other sites More sharing options...

0 Yoruichi-san Posted June 13, 2008 Report Share Posted June 13, 2008 (edited) I think I got it...the third one was throwing me off until I thought of n-parity... I noticed that the decimal values corresponded to 8ths, so I put them all in terms of 8ths, and the values become: -32/8,-31/8,95/8,825/8,16449/8,134098/8 The differences between the numerators are then: 1=1^6, 126, 729=3^6, 15625=5^6, 117649=7^6 So I was confused since the 2nd transition didn't match (2^6=64) until I realized that -(-31)+64=95, and 2 is the only *even* number in the bunch... So I think the formula should be as below: a(i) denotes the ith number in the sequence, starting with i=0 (I start at a(0), that is, -4=a(0), -3.875=a(1), etc) n(i) denotes the ith prime number, counting 1 (so 1,2,3,5,7,11,etc...) The formula should be a(i)={[(-1)^(n(i)-1)]*[a(i-1)*8]+ n(i)^6}/8 or formatted to be easier to read(I hope i did it right): a_{i} = {(-1)^{(n}_{i}^{-1)}(a_{i-1}*8)+n_{i}^{6}}/8 The (-1)^(n(i)-1)=1 for all odd n(i), so it only effects the sign of n(i)=2, which solves that issue... Anyways, I hope all my parentheses are in the right places, but I get that the next number in the sequence = (134098+11^6)/8=1905659/8 =238207.375 Oh, this also works if you use n(i)+1 or n(i)+3 or n(i)-3 or any n(i)+/-2(integer) instead of n(i)-1 as the exponent...the only thing that matters is the even/odd parity Nice sequence Data! I'm still working on the one in the newest post... Edited June 13, 2008 by Yoruichi-san Quote Link to comment Share on other sites More sharing options...

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## Guest

Find the next number in the pattern.

Easy

17, 18, 20, 23, 28, 35, ?

Medium

0, 1, 8, 38, 403, ?

Hard (let's see how long it will take you...)

-4, -3.875, 11,875, 103, 2056.125, 16762.25, ?

If you find that you can't arrive at an answer: 1. Your not good enough at math. or 2. I made a mistake in my math or there is some sort of typo.

Good luck!

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