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A092871
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Count of composites < 10^n.
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0
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4, 73, 830, 8769, 90406, 921500, 9335419, 94238543, 949152464, 9544947487, 95881945185, 962392087980, 9653934463159, 96795058249196, 970155429577329, 9720761658966073, 97376442842345765, 975260045712259138
(list; graph; refs; listen; history; internal format)
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OFFSET
| 1,1
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COMMENTS
| The number 1 is omitted from the count as it is neither prime nor composite
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LINKS
| C. Caldwell, The Prime Pages, How many primes are there? Table 1. Values of pi(x).
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FORMULA
| Subtract prime count from 10^n. From result subtract 2 to omit 1 and number at 10^n itself.
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EXAMPLE
| 10^3=1000. 1000-2=998. a(3)=830 because the 830 composites+168 primes must total 998.
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MATHEMATICA
| Table[10^i-PrimePi[10^i]-2, {i, 14}] (* From Harvey P. Dale, Oct 01 2011 *) (* Mathematica's implementation of PrimePi does not work for 10^15 or above *)
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CROSSREFS
| Cf. A065894, A006880, A092801, A092802.
Sequence in context: A055556 A168299 A089665 * A090212 A137046 A104335
Adjacent sequences: A092868 A092869 A092870 * A092872 A092873 A092874
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KEYWORD
| easy,nonn
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AUTHOR
| Enoch Haga (Enokh(AT)comcast.net), Mar 08 2004
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