A200655 - OEIS

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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: A081453 A352105 A345343 * A249439 A276693 A127050

Adjacent sequences: A200652 A200653 A200654 * A200656 A200657 A200658

KEYWORD

nonn

AUTHOR

Pierre CAMI, Nov 21 2011

STATUS

approved