20060114, 17:13  #12  
Nov 2003
2×1,811 Posts 
Quote:


20060114, 17:30  #13 
Nov 2003
2·1,811 Posts 
n=57
Found first DodecaProth for n=57:
87653084113035 57 And imagine, for such a small k<100T. Has one extra leg to the left, none to the right. 
20060114, 18:15  #14 
"Robert Gerbicz"
Oct 2005
Hungary
2^{2}×367 Posts 
No more dodecaproth for n=52
I've searched the full range for n=52 to find all dodecaproth.
Here is the full report: on Pentium4 Celeron 1.7 GHz: C:\>dodeca_1_0 52 1 4503599627370495 You can also find the k n values in results_dodeca.txt file ( These are 3probable primes ) n=52, kmin=1, kmax=4503599627370495, version=1.0 Starting the sieve... Using the first 10 primes to reduce the size of the sieve array 2808528662035845 52 The sieving is complete. Number of Prp tests=613089 Time=8917 sec. Ps. I've verified all 12 numbers are primes. Last fiddled with by R. Gerbicz on 20060114 at 18:17 
20060114, 18:15  #15 
Sep 2004
UVic
46_{16} Posts 
I don't get all the other stuff with legs and everything. just ran the program (dodeca_1_0.exe) here's what I got:
n=66, kmin=1, kmax=1000000000000000, version=1.0 Starting the sieve... Using the first 10 primes to reduce the size of the sieve array 229350894172785 66 The sieving is complete. Number of Prp tests=138495 Time=2992 sec. 
20060114, 18:36  #16  
"Robert Gerbicz"
Oct 2005
Hungary
2^{2}×367 Posts 
Probably we can start a new thread for reservation for dodecaproth search, to avoid the duplication.
Quote:
Last fiddled with by R. Gerbicz on 20060114 at 18:39 

20060115, 00:58  #17 
Nov 2003
2·1,811 Posts 
Congrats to tcadigan for a new DodecaProth! I found 3 for n=62:
99828673281855 62 286846836764775 62 1692654062704395 62 BTW, I checked n=56 to 1200T (1.2E15) and n=5762 to 2000T (2E15) but besides the one for n=57 I found none. I'm proceeding with n=6370 to 2000T (will skip n=66). 
20060115, 10:23  #18 
Nov 2003
2×1,811 Posts 
R. Gerbicz
I noticed a large slowdown of dodeca.exe ver. 1.0 on a large range. Have a look. Case 1:
Code:
n=70, kmin=15, kmax=3000000000000000, version=1.0 Using the first 10 primes to reduce the size of the sieve array Time=1968 sec. Code:
n=70, kmin=3000000000000000, kmax=10000000000000000, version=1.0 Using the first 11 primes to reduce the size of the sieve array Status: 0.3 percentage of the project is complete. Time thusfar: 69 sec. BTW, I checked all n=6770 to 3000T but found no new DodecaProths. Last fiddled with by Kosmaj on 20060115 at 10:26 
20060115, 12:05  #19  
"Robert Gerbicz"
Oct 2005
Hungary
5BC_{16} Posts 
Quote:
I'll see it. Yesterday I have not calculated this, but I thought that there will be such a problem using many primes in the sieving area ( first 11 primes means we are using primes up to 31 ). Probably this occured because we are sieving more numbers ( 12 numbers ). 

20060115, 13:24  #20 
Nov 2003
2·1,811 Posts 
All right, thanks.
BTW, I just ran into the first DodecaProth for n=70: 14494401979227555 70 [2E16] Note that k has 17 digits. k*2^n+/1 members have 38, while 2^n+/k have 22 digits. One leg on the left and one on the right. I'm also enclosing a Pari script I use to verify DodecaProths and count legs. To use it start Pari from the folder where you saved the file, then type: Code:
gp> read("isddp.txt") gp> isddp(14494401979227555,70) 14494401979227555 70 is DodecaProth! ... Left_legs=1, Rigth_legs=1. 
20060115, 13:29  #21 
Nov 2003
7046_{8} Posts 
All right, thanks.
BTW, I just ran into the first DodecaProth for n=70: 14494401979227555 70 [2E16] Note that k has 17 digits. k*2^n+/1 members have 38, while 2^n+/k have 22 digits. One leg on the left and one on the right. I'm also enclosing a Pari script I use to verify DodecaProths and count legs. To use it start Pari from the folder where you saved the file, then type: Code:
gp> read("isddp.txt") gp> isddp(14494401979227555,70) 14494401979227555 70 is DodecaProth! ... Left_legs=1, Rigth_legs=1. 
20060115, 13:44  #22 
"Robert Gerbicz"
Oct 2005
Hungary
1468_{10} Posts 
New dodeca program version 2.0
This is faster than dodeca 1.0, but the speed up is very very different for different n values and ranges.
To obtain this I've eliminated almost all modular multiplications ( in the part when we see if "g" is good or not ). Now magic_constant=32000 is good for this version. I'll think what would be a good "default" value. But note that we are sieving also up to 32000 and one block length is also 32000. Kosmaj can you test this version, I've checked only for n=44,47. And test your previous case 1 and case 2. You can download exe for windows from: http://www.robertgerbicz.tar.hu/dodeca_2_0.exe Or see the attachment for the c code. Last fiddled with by R. Gerbicz on 20060115 at 13:49 