Well, for GCSE, our teacher gave us this sequence and told us to find the nth term. Well, unsurprisingly, he did not tell us how to do it. Thats just what he's like. So, I decided to post here for help, because we have some intellectual people here =] So, the sequence is--> 11, 44, 110, 220, 385 1st difference --> 33, 66, 110, 165 2nd difference --> 33, 44, 55 3rd difference --> 10, 10

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http://answers.yahoo.com/question/index?qi...13024836AAFyEPv

from what I can tell the equation to find the nth term would be:
11/6(n^3) + 11(n^2) + 121/6(n) + 11 = nth term

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Hello,
the ninth term is 1815.
the full sequence it:
11,44,110,220,385,616,924,1320,1815
1st difference --> 33,66,110,165,231,308,396,495
2nd difference --> 33,44,55,66,77,88,99
3rd difference --> 10,10,10,10,10,10

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I LOVE YOU GUYS!!

Thanks DarkPsycho

and I really hope demonlord was joking!!

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No problem
Just a little Google Search did the trick.

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ZOMG! I cant read that ... you must be like geniuses .. LOLOL

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Lol, well I still had to learn how to find the nth term of a cubic sequence, so there wasn't much point in copying anyway.

Me and my friend discussed it over break-time, and we figured it out. It took about 4 A4 sized papers though lol =]

(even though the above equation was correct, google searches are usually junk)

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Then again, if you divide all the terms by 11, you get something from Pascal's Triangle:

11, 44, 110, 220, 385, ...

becomes

1, 4, 10, 20, 35, ...

which would break down into the first, second, and third differences as demonlord described, only divided by 11.

Only, isn't the third difference 11 instead of 10?

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