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A087933 Numbers n such that there are a prime number of primes less than 2^n. 0
2, 11, 31, 97, 12251, 564163 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

The next entry is greater than 2^44 as 2^45 exceeds The Nth Prime Page.

LINKS

Table of n, a(n) for n=1..6.

PROG

(PARI) primeslessxn2(n, p) = \primes < p^n if prime { sr=0; for(x=0, n, y=pi(p^x); if(y<>0, sr+=1.0/y); if(isprime(y), print1(y", ")); ); print(); print(sr) }

CROSSREFS

Sequence in context: A106847 A092761 A296733 * A190259 A190261 A000755

Adjacent sequences:  A087930 A087931 A087932 * A087934 A087935 A087936

KEYWORD

nonn

AUTHOR

Cino Hilliard, Oct 27 2003

STATUS

approved

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Last modified June 15 20:50 EDT 2019. Contains 324145 sequences. (Running on oeis4.)