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A118665 Least prime p such that n*(p#^3)-1 is prime or 0 if n is a cube so no prime possible. 0
2, 3, 2, 2, 5, 2, 3, 0, 2, 2, 59, 2, 2, 3, 11, 2, 3, 19, 2, 401, 2, 3, 3, 2, 2, 7, 0, 2, 3, 2, 13, 3, 2, 2, 3, 7, 7, 11, 2, 5, 5, 17, 7, 5, 2, 2, 2, 3, 2, 31, 3, 13, 257, 3, 2, 2, 5, 41, 2, 3, 2, 2, 31, 2, 0 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..65.

EXAMPLE

1*(2^3)-1=7 prime so a(1)=2

2*(2^3)-1=15 composite

2*((2*3)^3)-1=431 prime so a(2)=3

CROSSREFS

Sequence in context: A163873 A292588 A225176 * A225243 A207338 A027746

Adjacent sequences:  A118662 A118663 A118664 * A118666 A118667 A118668

KEYWORD

nonn

AUTHOR

Pierre CAMI, May 19 2006

STATUS

approved

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Last modified December 17 14:12 EST 2018. Contains 318201 sequences. (Running on oeis4.)