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A200655 a(n)= least number k > a(n-1) such that k*(2^p-1)*(k*(2^p-1)+1)-1 is prime, where p = A000043(n) = Mersenne exponents. 0
1, 3, 5, 7, 8, 19, 20, 23, 96, 190, 312, 400, 434, 852, 980, 1063, 1208, 3960, 5464, 6694, 7178, 13118, 13680, 18803, 27445, 28541, 42031, 73209, 83873 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

COMMENTS

a(n) is not so far from p

All certified primes using PFGW64 from primeform group

LINKS

Table of n, a(n) for n=1..29.

CROSSREFS

Cf. A000043, A121370

Sequence in context: A229860 A081453 A345343 * A249439 A276693 A127050

Adjacent sequences:  A200652 A200653 A200654 * A200656 A200657 A200658

KEYWORD

nonn

AUTHOR

Pierre CAMI, Nov 21 2011

STATUS

approved

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Last modified September 22 02:48 EDT 2021. Contains 347605 sequences. (Running on oeis4.)