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A100014 Least a(n) such that a(n)*2^n*(2^n-1)+1 is prime. 0
1, 1, 2, 1, 6, 3, 5, 12, 3, 5, 8, 6, 5, 3, 18, 8, 41, 5, 11, 14, 66, 8, 2, 9, 18, 8, 21, 12, 30, 16, 6, 1, 6, 8, 33, 2, 53, 23, 2, 5, 21, 15, 6, 12, 20, 5, 5, 28, 53, 80, 11, 53, 9, 5, 56, 2, 120, 5, 23, 16, 9, 8, 5, 9, 24, 25, 62, 131, 41, 51, 12, 3, 99, 56, 2, 37, 155, 3, 23, 55, 29, 9, 2, 33 (list; graph; refs; listen; history; internal format)
OFFSET

1,3

EXAMPLE

1*2^5*(2^5-1)+1=993=3*331

2*2^5*(2^5-1)+1=1985=5*397

3*2^5*(2^5-1)+1=2977=13*229

4*2^5*(2^5-1)+1=3969=3*1323

5*2^5*(2^5-1)+1=4961=11*451

6*2^5*(2^5-1)+1=5953 prime so a(5)=6

CROSSREFS

Sequence in context: A160047 A097288 A171178 * A062566 A126265 A124441

Adjacent sequences:  A100011 A100012 A100013 * A100015 A100016 A100017

KEYWORD

easy,nonn

AUTHOR

Pierre CAMI (pierre-cami(AT)bbox.fr), Nov 18 2004

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Last modified February 17 14:19 EST 2012. Contains 206038 sequences.