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$$0,1,1,1,1,2,1,1,1,2,1,2,1,2,2,1,1,2,1,2,2,2,1,2,1,2,1,2,1,\cdots$$

Wolfram alpha says that it is the number of distinct primes in n. Does it have another closed form? (This is from an introductory book on fourier series)

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    For such questions it's always a good idea to consult the [OEIS](http://oeis.org/search?q=0%2C1%2C1%2C1%2C1%2C2%2C1%2C1%2C1%2C2%2C1%2C2%2C1%2C2%2C2%2C1%2C1%2C2%2C1%2C2%2C2%2C2%2C1%2C2%2C1%2C2%2C1%2C2%2C1&language=english&go=Search)2011-04-18
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    If you drop the initial $0$, you can find more possibilities in the [OEIS](http://oeis.org/search?q=1%2C1%2C1%2C1%2C2%2C1%2C1%2C1%2C2%2C1%2C2%2C1%2C2%2C2%2C1%2C1%2C2%2C1%2C2%2C2%2C2%2C1%2C2%2C1%2C2%2C1%2C2%2C1) meaning that the next term can plausibly be $3$, $4$ or $5$2011-04-18

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