PURPOSE OF THE PROJECT
The Lange Number Line Project, abbreviated LNL, is an independent computational project for calculating, encoding and examining Collatz trajectories.
LNL does not claim to prove the Collatz conjecture.
The current goals are:
Calculate individual Collatz trajectories exactly.
Create reproducible operation codes for every tested trajectory.
Detect trajectory peaks and possible path-record candidates.
Compare the software with established reference results.
Publish code and data so that other people can reproduce or challenge the calculations.
The LNL terminology is an additional descriptive layer. Every numerical result remains based on the standard Collatz operations.
STANDARD COLLATZ RULE
For every positive integer n:
If n is even:
T(n) = n / 2
If n is odd:
T(n) = 3*n + 1
The trajectory of n is:
n, T(n), T(T(n)), and so on.
The calculation continues until the trajectory reaches 1.
TRAJECTORY PEAK
The trajectory peak P(n) is the largest number reached by the complete trajectory, including the starting value.
In plain notation:
P(n) = maximum value in the trajectory starting at n
The peak position is the first step at which this maximum is reached.
PATH RECORD
A starting value n is a path record only if its peak is higher than the peak of every smaller positive starting value.
In plain notation:
P(n) > P(m) for every m < n
This distinction is important.
Finding a very large peak for one sampled starting value does not prove that the starting value is the next path record.
To confirm the next path record, every smaller starting value must first be checked.
STANDARD OPERATION CODE
LNL records every standard operation with one letter:
U = odd operation: n becomes 3*n + 1
D = even operation: n becomes n / 2
A complete trajectory can therefore be stored as a sequence of U and D operations.
ACCELERATED ODD-STEP CODE
For every odd number x, LNL calculates:
d = v2(3*x + 1)
Here, v2 means the number of times that 3*x + 1 can be divided by 2 before the result becomes odd.
The next odd number is:
next odd x = (3*x + 1) / 2^d
The resulting list of d-values is a compact encoding of the standard Collatz trajectory.
This is not a new Collatz rule. It is only a shorter representation of the same operations.
CURRENT SOFTWARE
The current LNL software includes:
A deterministic path-record scanner
Exact 128-bit calculations
Exact 256-bit calculations
Exact 512-bit calculations
U and D trajectory codes
Accelerated d-value codes
Reproducible independent seed blocks
Overflow protection
Python arbitrary-precision verification
JavaScript BigInt verification
Residue-class and transition tests
The 512-bit C++ scanner compiles without warnings using:
-Wall -Wextra -Wconversion -Werror
REFERENCE VALIDATION
Before performing experimental searches, we tested the core software against established Collatz path records.
An exhaustive calculation of every starting value from 1 through 100,000,000 reproduced 41 successive path records.
The final path record in this interval is:
Start:
80,049,391
Peak:
2,185,143,829,170,100
Peak position:
164
Total steps to 1:
572
The results agree with the published reference sequences OEIS A006884 and OEIS A006885.
Reference links:
https://oeis.org/A006884
https://oeis.org/A006885
https://pcbarina.fit.vutbr.cz/path-records.htm
ARBITRARY-PRECISION EXAMPLE
As a separate large-number test, LNL calculated the trajectory of:
n = 10^1001
This number is exactly a 1 followed by 1,001 zeros.
It has 1,002 decimal digits.
Because:
10^1001 = 2^1001 * 5^1001
the trajectory begins with exactly 1,001 divisions by 2.
After these divisions, the odd core is:
5^1001
Exact results:
Starting value:
10^1001
Decimal digits:
1,002
Binary length:
3,326 bits
Trajectory peak:
10^1001
Peak position:
0
Total steps to 1:
17,840
Odd 3*n + 1 steps:
5,615
Even n / 2 steps:
12,225
Control calculation:
5,615 + 12,225 = 17,840
The starting value itself is the peak. The trajectory never returns to or exceeds it.
Python arbitrary-precision integers and JavaScript BigInt independently produced the same result.
SAMPLED HIGH-NUMBER SEARCHES
LNL has also calculated individual trajectories for sampled starting values far beyond the exhaustively tested interval.
Some of these trajectories reach extremely large exact values.
These experiments demonstrate that:
The software can process very large integers.
The individual trajectories can be reproduced.
The 512-bit engine works beyond the normal 64-bit range.
These results do not establish new path records.
At very large starting values, the starting value itself may already be larger than an older published peak.
For this reason, these results are described only as:
Exact sampled trajectories
or:
Sampled height exceeders
They are not described as confirmed world records.
WHAT LNL DOES NOT CLAIM
LNL does not currently claim:
A proof of the Collatz conjecture
Proof that every positive integer reaches 1
Discovery of the next official path record
Exhaustive verification beyond the stated limits
That sampled searches can replace exhaustive calculations
That every descriptive LNL term is mathematically new
NEXT SCIENTIFIC GOAL
The next goal is not simply to generate a larger number.
The next goal is to improve reproducibility.
PHASE 1: PUBLIC SOFTWARE RELEASE
Publish:
C++ source code
Python verification code
Compiler commands
Exact definitions
Test results
CSV result tables
SHA-256 file hashes
PHASE 2: EXHAUSTIVE EXTENSION
Extend the deterministic path-record calculation from:
100,000,000
toward:
1,000,000,000
No starting values may be skipped.
PHASE 3: INDEPENDENT VERIFICATION
Every detected path record must be recalculated with a separate arbitrary-precision implementation.
A result will be called a path record only after every smaller starting value in the interval has been checked.
PHASE 4: STRUCTURAL ANALYSIS
After the numerical baseline is secure, we will examine whether U/D codes, d-value sequences and inverse structures contain useful predictive information.
INVITATION TO REPRODUCE OR CRITICIZE
Technical criticism is welcome.
A reproducible countercheck should include:
The exact starting value.
The Collatz convention used.
The source code or algorithm.
The first trajectory position where the results differ.
The integer type and overflow protection.
Whether the starting value is included in the peak definition.
The purpose of LNL is not to replace established mathematics with graphics or terminology.
The purpose is to build a transparent computational framework whose results can be independently reproduced, tested, criticized and improved.
Copyright (c) 2026 Mike Lange
Lange Number Line Project (LNL)
All rights reserved.