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A000849
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Number of primes <= product of first n primes, A002110(n).
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21
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0, 1, 3, 10, 46, 343, 3248, 42331, 646029, 12283531, 300369796, 8028643010, 259488750744, 9414916809095, 362597750396740, 15397728527812858, 742238179058722891, 40068968501510691894, 2251262473052300960826, 139566579945945392719413
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OFFSET
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0,3
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LINKS
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FORMULA
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MAPLE
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seq(numtheory:-pi(mul(ithprime(i), i=1..n)), n=0..10); # Robert Israel, Aug 25 2014
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MATHEMATICA
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a=1; Table[a=a*Prime[n]; PrimePi[a], {n, 12}]
Join[{0}, PrimePi/@FoldList[Times, Prime[Range[12]]]] (* Harvey P. Dale, Jan 28 2019 *)
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PROG
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(PARI) t=1; forprime(p=2, 66, print1(primepi(t), ", "); t*=p); \\ Joerg Arndt, Aug 25 2014
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CROSSREFS
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KEYWORD
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nonn,hard
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AUTHOR
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James D. Ausfahl, gandalf(AT)hrn.office.ssi.net
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EXTENSIONS
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STATUS
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approved
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