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A054270 Largest prime below prime(n)^2 (A001248). 6
3, 7, 23, 47, 113, 167, 283, 359, 523, 839, 953, 1367, 1669, 1847, 2207, 2803, 3469, 3719, 4483, 5039, 5323, 6229, 6883, 7919, 9403, 10193, 10607, 11447, 11867, 12763, 16127, 17159, 18757, 19319, 22193, 22787, 24631, 26561, 27883, 29927, 32029 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

For n > 1, the n-1 first primes determine the primes up to a(n). This is how the Sieve of Eratosthenes works. - Jean-Christophe Hervé, Oct 21 2013

LINKS

Table of n, a(n) for n=1..41.

FORMULA

a(n) = Max[prime q: q < prime(n)^2].

a(n) = prime(A000879(n)) = A000040(A000879(n)). - Jean-Christophe Hervé, Oct 21 2013

MATHEMATICA

NextPrime[Prime[Range[50]]^2, -1] (* Harvey P. Dale, May 19 2016 *)

PROG

(PARI) a(n) = precprime(prime(n)^2); \\ Michel Marcus, Dec 13 2013

CROSSREFS

Cf. A001248, A054271.

Sequence in context: A216816 A079477 A014426 * A058000 A246497 A002715

Adjacent sequences:  A054267 A054268 A054269 * A054271 A054272 A054273

KEYWORD

nonn

AUTHOR

Labos Elemer, May 05 2000

STATUS

approved

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Last modified September 24 07:30 EDT 2018. Contains 315308 sequences. (Running on oeis4.)