OFFSET
1,1
COMMENTS
Another term is a(51)=854. All values have been proved prime. Primality proof for a(51), which has 10175 digits: PFGW Version 1.2.0 for Windows [FFT v23.8] Primality testing 854*(279978 ... [digits deleted] ... 823983)^51-1 [N+1, Brillhart-Lehmer-Selfridge] Reading factors from helper file help.txt Running N+1 test using discriminant 5, base 4+sqrt(5) Calling Brillhart-Lehmer-Selfridge with factored part 50.07% 854*(279978 ... [digits deleted] ... 823983)^51-1 is prime! (68.4205s+0.0510s) ======== Also, the Primeform e-group found 25987968300*[RSA-200]^512-1 and 49334180280*[RSA-200]^512-1, each with 102128 digits (see link).
LINKS
Chris Caldwell, Primeform e-group bio.
Wikinews, 200 Digit Number Factored.
CROSSREFS
KEYWORD
nonn
AUTHOR
Jason Earls, Jul 02 2005
EXTENSIONS
a(12)-a(40) from Max Alekseyev, Feb 02 2010
STATUS
approved