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.".

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)

Links

Table of n, a(n) for n=1..33.

Crossrefs

Cf. A108344.

Sequence in context: A044717 A235990 A270300 * A258549 A121962 A235011

Adjacent sequences: A108662 A108663 A108664 * A108666 A108667 A108668

Keyword

more,nonn

Author

Jason Earls, Jul 07 2005

Status

approved