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A108665
Least positive k such that k * Y^n + 1 is prime, where Y = 2^100+277, the first prime greater than a "little googol.".
0
104, 208, 696, 1522, 486, 24, 96, 1020, 374, 220, 198, 4228, 272, 598, 854, 408, 1826, 438, 1760, 232, 170, 130, 186, 1216, 4812, 4450, 1878, 1236, 434, 28, 5036, 406, 656
OFFSET
1,1
COMMENTS
Other terms are a(100)=2772, a(150)=3652, a(200)=10242 and a(300)=2740. All values have been proved prime. Primality proof for a(300), which has 9035 digits: PFGW Version 1.2.0 for Windows [FFT v23.8] Primality testing 2740*(1267650600228229401496703205653)^300+1 [N-1, Brillhart-Lehmer-Selfridge] Reading factors from helper file help.txt Running N-1 test using base 2 Calling Brillhart-Lehmer-Selfridge with factored part 99.96% 2740*(1267650600228229401496703205653)^300+1 is prime! (12.1861s+0.0046s)
CROSSREFS
Cf. A108344.
Sequence in context: A044717 A235990 A270300 * A258549 A121962 A235011
KEYWORD
more,nonn
AUTHOR
Jason Earls, Jul 07 2005
STATUS
approved