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A051888 a(n) = smallest prime p such that p*n! + 1 is prime. 7
2, 2, 2, 2, 3, 2, 3, 3, 7, 3, 3, 5, 2, 3, 13, 7, 31, 5, 2, 7, 17, 67, 41, 3, 13, 3, 43, 17, 97, 7, 29, 109, 3, 71, 5, 2, 7, 41, 3, 59, 3, 11, 29, 7, 107, 67, 79, 3, 743, 149, 163, 2, 211, 2, 19, 71, 73, 23, 37, 113, 149, 67, 41, 617, 107, 37, 107, 283, 113, 19, 239, 107, 73, 97, 5 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,1

LINKS

Table of n, a(n) for n=0..74.

FORMULA

Analogous to or subset of A051686; generalization of A005384

MATHEMATICA

Do[k = 1; While[ !PrimeQ[ Prime[k]*n! + 1], k++ ]; Print[ Prime[k]], {n, 1, 75} ]

CROSSREFS

A005384, A051686, A051886, A051887.

Sequence in context: A070098 A029233 A147981 * A088019 A178930 A126759

Adjacent sequences:  A051885 A051886 A051887 * A051889 A051890 A051891

KEYWORD

nonn

AUTHOR

Labos E. (labos(AT)ana.sote.hu), Dec 15 1999

EXTENSIONS

More terms from James A. Sellers, Dec 16 1999

STATUS

approved

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Last modified May 25 23:56 EDT 2013. Contains 225650 sequences.