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A201361 Numbers n such that (2^n - n + 1)*2^n - 1 is prime. 7
1, 2, 3, 8, 14, 35, 75, 83, 89, 90, 215, 342, 753, 1452, 4578 (list; graph; refs; listen; history; text; internal format)
OFFSET

1,2

LINKS

Table of n, a(n) for n=1..15.

EXAMPLE

3 is in the sequence because (2^3 - 3 + 1)*2^3 - 1 = 47 is prime.

MATHEMATICA

lst={}; Do[If[PrimeQ[(2^n - n+1)*2^n-1], AppendTo[lst, n]], {n, 10000}]; lst

CROSSREFS

Cf. A201356, A201357, A201358, A201359, A201360, A201362, A201363.

Sequence in context: A171237 A173149 A128305 * A129700 A197466 A049344

Adjacent sequences:  A201358 A201359 A201360 * A201362 A201363 A201364

KEYWORD

nonn,hard

AUTHOR

Michel Lagneau, Nov 30 2011

STATUS

approved

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Last modified November 23 19:50 EST 2014. Contains 249865 sequences.