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3 prime factor Charmichael number examples for roughly every 3 decimal digits up to 343
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| assert(b)=if(!(b),error()); | |
| factmul(f1,f2)=matreduce(matconcat([f1,f2]~)); | |
| factval(F)=vecprod([v[1]^v[2]|v<-F~]); | |
| {Redu=[0,25,0,25,110,291,51,146,131,511,111,95,1121,2685,820,12481,16175,1866, | |
| 4500,11525,8960,441,390,14796,1280,1651,1730,24140,21226,18555,43391,3716,2980, | |
| 46701,38580,15450,5560,19445,14376,83660,32560,7516,5060,23806,57806,44636, | |
| 28985,73445,60936,55146,91400,82190,54255,8016,25591,71945,259946,147035,11301, | |
| 3375,2371,18486,466191,436551,422806,6220,153406,493275,222755,1572896,453141, | |
| 5385,422511,663666,364225,84081,52590,916505,285466,827301,5671,137266,120160, | |
| 23755,202690,140935,503151,560981,1528285,2474481,527805,660190,391711, | |
| 1161251,2985,727031,984236,494371,311091,517321,289351,496466,143956,33130, | |
| 1394135,166086,484375,4787525,2336340,338141,50106,411670,822656,507900];} | |
| Car_3_m=Redu;for(i=1,#Redu,Car_3_m[i]=10^(i-1)+Redu[i]); | |
| Car_3_pqr=[pqr|m<-Car_3_m;p<-[6*m+1];q<-[12*m+1];r<-[18*m+1];pqr<-[[p,q,r]]]; | |
| Car_3_n=[n|pqr<-Car_3_pqr;n<-[pqr[1]*pqr[2]*pqr[3]]]; | |
| Car_3_npqr=[[n,p,q,r]|i<-[1..#Car_3_n];n<-[Car_3_n[i]];\ | |
| pqr<-[Car_3_pqr[i]];p<-[pqr[1]];q<-[pqr[2]];r<-[pqr[3]]]; | |
| Quick=Set(concat([1..38],\ | |
| [41,42,43,45,47,48,50,51,54,55,59,67,70,73,76,79,81,93,111,114])); | |
| Carfactorint(i)={ | |
| if(i==80, | |
| return([2,4;3,5;29,1;101,1;2879,1;3527,1;794593,1;154660403,1;1375778713,1; | |
| 82559127467,1;2191141520677,1;5244008545913,1;215523228663966371,1; | |
| 727945109737073604951121,1;3071482538062826439493217,1; | |
| 405473649637074755617787593281337701367,1; | |
| 357632907601311950933336045572973824205399821454828478880978313,1] | |
| ) | |
| ); | |
| [n,p,q,r]=Car_3_npqr[i]; | |
| np=(n-1)/gcd(n-1,p-1);npq=np/gcd(np,q-1);npqr=npq/gcd(npq,r-1); | |
| F=factmul(factorint((n-1)/npqr),factorint(npqr)); | |
| assert(n-1==factval(F)); | |
| F | |
| }; |
Author
Author
Efforts to determine other factorizations of n-1 for Carmichael numbers n:
https://www.mersenneforum.org/node/1106355?p=1106709#post1106709
New index 80 fully factorized, 63 decimal digits prime is largest prime factor of 241 decimal digits n-1:
hermann@j4105:~$ gp -q Car_3.343dd.gp
? n=Car_3_n[80];
? #digits(n)
241
? F=Carfactorint(80);
? ##
*** last result computed in 0 ms.
? n-1==factval(F)
1
? for(i=1,#F-1,if(F[i,1]>=F[i+1,1],print("wrong "i)))
? [isprime(p)|p<-F[,1]]
time = 1,088 ms.
[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1]
? print(Carfactorint(80))
[2, 4; 3, 5; 29, 1; 101, 1; 2879, 1; 3527, 1; 794593, 1; 154660403, 1; 1375778713, 1; 82559127467, 1; 2191141520677, 1; 5244008545913, 1; 215523228663966371, 1; 727945109737073604951121, 1; 3071482538062826439493217, 1; 405473649637074755617787593281337701367, 1; 357632907601311950933336045572973824205399821454828478880978313, 1]
?
Author
Chernick, Jack. “On Fermat's simple theorem.” Bulletin of the American Mathematical Society 45 (1939): 269-274.
https://www.ams.org/journals/bull/1939-45-04/S0002-9904-1939-06953-X/S0002-9904-1939-06953-X.pdf
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Nested infinite loops used to generate the compressed vector
Reduentries.Terminated after 2.5h real and 8.5h cpu time (PARI/GP
isprime()is multithreaded):