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Here is a set,

$$A = \{0,3,8,15,24,35,\ldots\}$$

I have to write its set builder notation. I am out of ideas. Can anyone please provide a hint?

Thanks

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    To your edit, $5=2+3\notin A$.2011-11-03
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    @AsafKaragila: Thanks. I revised the question again.2011-11-03
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    Note that there are many infinitely many ways to express that set since you need only have a representation that contains those 6 elements (and assuming that it is a non-decreasing order, that it does not contain all other elements less than $35$).2011-11-03

2 Answers 2

6

Notice that the terms are $1$ less than the perfect squares, so are of the form $ n^2 -1 . $ Then, we can write $$ A = \{ n^2-1 \mid n\in\mathbb{N} \} .$$

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    Hope you don't mind my tex edit.2011-11-03
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    @Rasmus Not at all. Feel free to improve the aesthetics of my posts anytime!2011-11-03
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Look at the differences $8-3$, $15-8$, $24-15$, $35-24$.