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CraigLo · 2021-08-24, 20:45

There is a list of base 2 pseudoprimes up to 2⁶⁴.
http://www.janfeitsma.nl/math/psp2/index

When you guys were doing the search up to 2⁶⁴ it would have been faster to do the Lucas test only if the number was a known 2-PSP.

Unfortunately the list only goes up to 2⁶⁴. Is there a fast way to generate the list of 2-PSP. When checking for gaps we need to do one Lucas test for every 1400 numbers. To check from 2⁶⁴ to 2⁶⁴ + 2.33 * 10¹⁶ (Gap=1552) would require 1.66*10¹³ Lucas tests. Can the list of 2-PSP be computed faster than this? We wouldn't even need to rerun what has already been done. We could just check for large gaps around the 2-PSPs.

2021-08-24, 20:45	#44
CraigLo Mar 2021 59 Posts	There is a list of base 2 pseudoprimes up to 2⁶⁴. http://www.janfeitsma.nl/math/psp2/index When you guys were doing the search up to 2⁶⁴ it would have been faster to do the Lucas test only if the number was a known 2-PSP. Unfortunately the list only goes up to 2⁶⁴. Is there a fast way to generate the list of 2-PSP. When checking for gaps we need to do one Lucas test for every 1400 numbers. To check from 2⁶⁴ to 2⁶⁴ + 2.33 * 10¹⁶ (Gap=1552) would require 1.66*10¹³ Lucas tests. Can the list of 2-PSP be computed faster than this? We wouldn't even need to rerun what has already been done. We could just check for large gaps around the 2-PSPs.