# Primes in different bases dating

### Largest known prime number - Wikipedia

students to look for patterns for the primes in different bases, but alas! the primes that the prime numbers from 5 upwards are of form 6n+1 or 6n-1; (but this. Here is the same question which has been asked at Mathforum: Here is the link. smena.info from the. So if you see a prime in base 2, then it's also a prime in base 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, so you'd do what you do in any of these bases.

No factor was found until a famous talk by Frank Nelson Cole in Searching for Mersenne primes[ edit ] Fast algorithms for finding Mersenne primes are available, and as of [update] the seven largest known prime numbers are Mersenne primes.

### Math Forum - Ask Dr. Math

After nearly two centuries, M31 was verified to be prime by Leonhard Euler in Two more M89 and M were found early in the 20th century, by R.

Powers in andrespectively. The best method presently known for testing the primality of Mersenne numbers is the Lucas—Lehmer primality test. During the era of manual calculation, all the exponents up to and including were tested with the Lucas—Lehmer test and found to be composite.

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A notable contribution was made by retired Yale physics professor Horace Scudder Uhler, who did the calculations for exponents,and Graph of number of digits in largest known Mersenne prime by year — electronic era. Note that the vertical scale, the number of digits, is doubly logarithmic in the value of the prime.

The search for Mersenne primes was revolutionized by the introduction of the electronic digital computer. Alan Turing searched for them on the Manchester Mark 1 in[9] but the first successful identification of a Mersenne prime, M, by this means was achieved at It was the first Mersenne prime to be identified in thirty-eight years; the next one, M, was found by the computer a little less than two hours later.

M is the first Mersenne prime that is titanicM44, is the first giganticand M6, was the first megaprime to be discovered, being a prime with at least 1, digits. The prize, finally confirmed in Octoberis for the first known prime with at least 10 million digits. The prime was found on a Dell OptiPlex on August 23, Prime numbers Hi Jorge, A prime is a prime no matter which base you use to represent it.

The example 21 doesn't work too well because it is not prime. The base ten number 37 is better, because it is prime, but its Hex representation is 25, which sort of looks non-prime.

## Mersenne prime

Hex 25 is not, however, repeat not, 5 squared. Okay, enough for examples.

The fact of being prime or composite is just a property of the number itself, regardless of the way you write it. That is the way it is for all numbers, in the sense that if a base ten number N has factors, you can represent those factors in Hex and their product will be the number N in Hex.

Relating to your question about base 13, the base ten number 13 will be represented as "10" in that system, but "10" will still be a prime, because you cannot find two numbers other than 1 and "10" that will multiply together to make "10". I hope this helps you think about primes in other bases. I don't have any insight into fractal geometry and primes, except to say that you will probably be wise to pursue your interest in chaos and fractals.

There may be something in there of interest for you to discover.