HP 41C Pollard Brent Integer Factorization

[Joe Horn]

(07-07-2014 06:04 AM)Jim Horn Wrote:  A modulo 210 brute force factoring on the HP-67 took 0.1042*sqrt(x) seconds in 1979. The HP-41 averaged 3 times that speed. So your example would take around 58 minutes. (CF "Finding Factors Faster", PPC Journal, mid-Cretaceous epoch, by some old phart)

Cool. Oh yeah, I forgot that it only needs to go up to the square root of the input, not the whole way. So instead of NP taking 38 years, it should take about 3 hours 20 minutes. Quite a difference!