Thread: GMP-ECM vs mprime for F12? View Single Post 2019-03-13, 04:49 #11 mathwiz   Mar 2019 7F16 Posts Interestingly, GMP-ECM only seems to use gwnum_ecmStage1() if the input is written out explicitly in (2^n +/- 1)/d form, as opposed to a full decimal. E.g.: Code: Input number is 7124875134919416452774071346240764917465050401053729788475829418006792633070197260773480462000925038600888030166963314178711084227927169505054967049906157236644045588489318562381444403587801123276191390920852492526599174604254696368010876509960456095578194840205874002033519141134093531142804832239163228700607998501023572045880402900991 (337 digits) Did not find a gwnum poly for the input number. Using special division for factor of 2^1243-1 but Code: Input number is (2^1243-1)/(2^113-1)/2047 (337 digits) Found number: 1*2^1243 + -1 Using special division for factor of 2^1243-1 Using B1=850000000, B2=15892628251516, polynomial Dickson(30), sigma=0:10702604903946832294 dF=524288, k=5, d=5705700, d2=17, i0=132 Expected number of curves to find a factor of n digits: 35 40 45 50 55 60 65 70 75 80 15 47 168 661 2867 13623 69471 381778 2221086 1.4e+07 Using gwnum_ecmStage1(1, 2, 1243, -1, 850000000, 1)  