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A007014 Largest prime <= Product prime(k).
(Formerly M1546)
6
2, 5, 29, 199, 2309, 30029, 510481, 9699667, 223092827, 6469693189, 200560490057, 7420738134751, 304250263527209, 13082761331669941, 614889782588491343, 32589158477190044657, 1922760350154212638963, 117288381359406970983181, 7858321551080267055878989 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

COMMENTS

A057705 contains terms of a(n) such that A002110(n) - a(n) = 1. -Michael De Vlieger, May 15 2017

REFERENCES

N. J. A. Sloane and Simon Plouffe, The Encyclopedia of Integer Sequences, Academic Press, 1995 (includes this sequence).

LINKS

Michael De Vlieger, Table of n, a(n) for n = 1..350

R. G. Wilson, V, Letter to N. J. A. Sloane, Jan. 1994

FORMULA

From Michael De Vlieger, May 15 2017: (Start)

a(n) = prime(A000849(n)).

a(n) = A151799(A002110(n)). (End)

EXAMPLE

From Michael De Vlieger, May 15 2017: (Start)

a(1) = 2 since A002110(1) = 2. 2 is prime thus the largest prime <= 2 = 2.

a(2) = 5 since A002110(2) = 6. 5 is the largest prime <= 6. (End)

MATHEMATICA

Array[Abs@ NextPrime[Product[Prime@ i, {i, #}], -1] &, 14] (* Michael De Vlieger, May 15 2017 *)

PROG

(PARI) lista(n) = {prd = 1; for (i=1, n, prd *= prime(i); print1(precprime(prd), ", "); ); } \\ Michel Marcus, Jun 17 2013

(PARI) a(n)=precprime(prod(i=1, n, prime(i))) \\ Charles R Greathouse IV, Jun 17 2013

CROSSREFS

Cf. A000849, A002110, A057705, A151799.

Sequence in context: A257163 A243276 A277005 * A265147 A098682 A108367

Adjacent sequences:  A007011 A007012 A007013 * A007015 A007016 A007017

KEYWORD

nonn

AUTHOR

N. J. A. Sloane, Mira Bernstein, Robert G. Wilson v

EXTENSIONS

Corrected by Jud McCranie, Jan 03 2001

More terms from Michael De Vlieger, May 15 2017

STATUS

approved

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Last modified March 19 04:34 EDT 2019. Contains 321311 sequences. (Running on oeis4.)