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A084730 Smallest prime of the form k*n! - 1. 1
2, 3, 5, 23, 239, 719, 5039, 201599, 1088639, 14515199, 159667199, 479001599, 31135103999, 87178291199, 2615348735999, 188305108991999, 711374856191999, 192071211171839999, 3649353012264959999, 12164510040883199999 (list; graph; refs; listen; history; text; internal format)
OFFSET

2,1

LINKS

Table of n, a(n) for n=2..21.

EXAMPLE

a(8) = 161599 = 4*8! - 1 is a prime.

MATHEMATICA

Do[k = 1; While[ !PrimeQ[k*n! - 1], k++ ]; Print[k*n! - 1], {n, 2, 20}]

PROG

(PARI) a(n)=if(n<1, 0, k=1; while(isprime(k*n!-1)==0, k++); k*n!-1)

CROSSREFS

Cf. A083663.

Sequence in context: A138655 A053708 A137070 * A117696 A256463 A279864

Adjacent sequences:  A084727 A084728 A084729 * A084731 A084732 A084733

KEYWORD

nonn

AUTHOR

Amarnath Murthy and Meenakshi Srikanth (menakan_s(AT)yahoo.com), Jun 13 2003

EXTENSIONS

Corrected and extended by Benoit Cloitre, Jun 14 2003

STATUS

approved

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Last modified October 22 01:46 EDT 2020. Contains 337948 sequences. (Running on oeis4.)