Ключевые слова: гипотеза Коллатца, числа-градины, ряды, алгоритм, последовательности, доказательства.
Annotation. When young mathematicians are told about this problem, they are immediately warned that it is not worth taking up its solution, because it seems impossible. A simple-looking hypothesis could not be proved by the best minds of mankind. For comparison, the famous mathematician Paul Erdos said: «Mathematics is not yet ripe for such questions.» However, it is worth studying this hypothesis in more detail, which is investigated in this paper.
Keywords: Collatz hypothesis, hailstone numbers, series, algorithm, sequences, proofs.
In short, its essence is as follows. A certain number is selected and if it is not even, it is multiplied by 3 and 1 is added, if it is even, then divided by 2.
We can give an algorithm of this series for the number 7:
7 – 22 – 11 – 34 – 17 – 52 – 26 – 13 – 40 – 20 – 10 – 5 – 16 – 8 – 4 – 2 – 1
Next, a cycle is obtained:
1 – 4 – 2 – 1 etc.
This leads to the hypothesis that if you take any positive integer, if you follow the algorithm, it necessarily falls into the cycle 4, 2, 1. The hypothesis is named after Lothar Collatz, who is believed to have come to this hypothesis in the 30s of the last century, but this problem has many names, it is also known as the Ulam hypothesis, Kakutani's theorem, Toitz's hypothesis, Hass's algorithm, the Sikazuz sequence, or simply as "3n+1".
How did this hypothesis gain such fame? It is worth noting that in the professional environment, the fame of such a hypothesis is very bad, so the very fact that someone is working on this hypothesis may lead to the fact that this researcher will be called crazy or ignorant.
The numbers themselves that are obtained during this transformation are called hailstones, because, like hail in the clouds, the numbers then fall, then rise, but sooner or later, all fall to one, at least so it is believed. For convenience, we can make an analogy that the values entered into this algorithm are altitude above sea level. So, if you take the number 26, then it first sharply decreases, then rises to 40, after which it drops to 1 in 10 steps. Here you can give a series for 26:
26 – 13 – 40 – 20 – 10 – 5 – 16 – 8 – 4 – 2 – 1
However, if we take the neighboring number 27, it will jump at a variety of heights, reaching the mark of 9,232, which, continuing the analogy, is higher than Mount Everest, but even this number is destined to collapse to the Ground, although it will take 111 steps to reach 1 and get stuck in the same loop. The same interesting numbers can be numbers 31, 41, 47, 54, 55, 62, 63, 71, 73, 82 and others. For comparison, we can analyze the table (Table 1) and the graph (Fig. 1) for these interesting numbers.
Table 1. A series of long numbers for interesting values of numbers-granules (the first line is the original value)
Table 1. A series of long numbers for interesting values of numbers-granules (the first line is the original value)
Table 1. A series of long numbers for interesting values of numbers-granules (the first line is the original value)
Table 1. A series of long numbers for interesting values of numbers-granules (the first line is the original value)
Table 1. A series of long numbers for interesting values of numbers-granules (the first line is the original value)
Table 1. A series of long numbers for interesting values of numbers-granules (the first line is the original value)
Table 1. A series of long numbers for interesting values of numbers-granules (the first line is the original value)