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A098915 Least k such that k*Mersenne-prime(n)*Mersenne-prime(n+1) - 1 is prime. 0
2, 2, 2, 24, 2, 50, 6, 26, 14, 306, 86, 846, 104, 1832 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,1

LINKS

Table of n, a(n) for n=1..14.

EXAMPLE

2*(2^2-1)*(2^3-1) - 1 = 41 prime so k(1)=2

2*(2^3-1)*(2^5-1) - 1 = 433 prime so k(2)=2

CROSSREFS

Sequence in context: A140283 A067097 A260082 * A095855 A157979 A147975

Adjacent sequences:  A098912 A098913 A098914 * A098916 A098917 A098918

KEYWORD

nonn

AUTHOR

Pierre CAMI, Oct 17 2004

STATUS

approved

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Last modified November 18 04:44 EST 2019. Contains 329248 sequences. (Running on oeis4.)