20190809, 18:55  #12 
"Carlos Pinho"
Oct 2011
Milton Keynes, UK
3·1,549 Posts 
Go to the computer stats and try to find one available with processed wus. Click on that wu to see its details. For example: https://boinc.thesonntags.com/collat...ultid=40998456

20190810, 05:00  #13 
Romulan Interpreter
Jun 2011
Thailand
2^{2}×17×127 Posts 
Down for maintenance :)

20190810, 07:20  #14 
"Carlos Pinho"
Oct 2011
Milton Keynes, UK
1227_{16} Posts 
Code:
<core_client_version>7.9.3</core_client_version> <![CDATA[ <stderr_txt> Collatz Conjecture Sieve 1.40 Linux x86_64 for OpenCL Written by Slicker (Jon Sonntag) of team SETI.USA Based on the AMD Brook+ kernels by Gipsel of team Planet 3DNow! Sieve code and OpenCL optimization provided by Sosiris of team BOINC@Taiwan kernels_per_reduction=48 threads=7 lut_size=19 sleep=1 reduce_cpu=0 sieve_size=30 Collatz Config Settings: verbose 1 (yes) kernels/reduction 48 threads 2^7 (128) lut_size 19 (4194304 bytes) sieve_size 2^30 (51085096 bytes) sleep 1 cache_sieve 1 (yes) reducecpu 0 (no) Processor Type NVIDIA Max Dimensions 3 Max Work Items 1024 1024 64 Max Work Groups 1024 Max Kernel Threads 1024 Device Vendor NVIDIA Corporation Name TITAN V Driver Version 418.67 OpenCL Version OpenCL 1.2 CUDA Device Vendor NVIDIA Corporation Name TITAN V Driver Version 418.67 OpenCL Version OpenCL 1.2 CUDA actual threads 128 6170811732209765980839  1179 steps @ 1.40482 6170811732237683321243  1334 steps @ 1.40489 6170811732233929053031  1528 steps @ 1.40492 6170811732534651731455  1608 steps @ 2.80589 6170811732889754196991  1727 steps @ 4.4327 6170811734370780556927  1833 steps @ 11.2197 6170811734412937127423  1851 steps @ 11.4509 6170811774127834587775  1970 steps @ 191.823 Start 6170811732191512363008 Stop 6170811784968070496256 Best 6170811774127834587775 Highest steps 1970 Total steps 396855723221023 CPU time 3.80772 seconds Elapsed time 00:03:56 19:42:25 (25184): called boinc_finish </stderr_txt> ]]> 
20190821, 17:17  #16 
"David Barina"
Jul 2016
Brno
41_{8} Posts 
Computational verification of Collatz problem
Would anyone be willing to implement this verification procedure effectively (in any programming language) and verify it for higher limits? The underlying operation should nicely fit to modern instruction sets (namely the TZCNT in BMI1 set).
Thanks, David 
20190821, 18:03  #17 
6809 > 6502
"""""""""""""""""""
Aug 2003
101×103 Posts
20FA_{16} Posts 
MOD Note: Three very small threads about the Collatz problem/conjecture have been merged.

20190821, 20:16  #18 
"Dylan"
Mar 2017
2^{2}·5^{3} Posts 
I have written a program in python to implement this procedure: see the attached pdf with the code. I do indeed get the same sequence of n's with this as in the stackexchange post, but the σ's and ε's don't seem to match up. It appears for those in that post you have the values for n+1 (for example, for 27 you have σ = 7, ε = 2 which would yield n = 7*2^2 = 28).

20190822, 12:59  #19  
"David Barina"
Jul 2016
Brno
100001_{2} Posts 
Quote:


20190822, 15:16  #20 
"Dylan"
Mar 2017
2^{2}·5^{3} Posts 
I checked my implementation with yours and it appears to be the same as mine. I managed to match your sigma and epsilon values in my python code by simply changing
Code:
decomp(n) Code:
decomp(n+1) Also, your C code doesn't work in Windows using mingw64  I get an assertion failed in line 25 of the code, regardless of the input. That is where you do the 3^n bit. 
20190822, 17:22  #21  
"David Barina"
Jul 2016
Brno
3·11 Posts 
Quote:


20190826, 13:51  #22 
"David Barina"
Jul 2016
Brno
3·11 Posts 
Greetings,
My current singlethreaded implementation gives the throughput about 3.99 × 10^9 128bit numbers per seconds. Any help is welcome! 
Thread Tools  
Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
Collatz 3x+1 problem  Cybertronic  Miscellaneous Math  4  20190320 08:40 
Collatz Conjecture Proof  Steve One  Miscellaneous Math  21  20180308 08:18 
this thread is for a Collatz conjecture again  MattcAnderson  MattcAnderson  16  20180228 19:58 
Collatz conjecture  MattcAnderson  MattcAnderson  4  20170312 07:39 
Related to Collatz conjecture  nibble4bits  Math  1  20070804 07:09 