# Write a program in c to find prime numbers from 1 to 100

Even if this were corrected, the question code produces very slow output because it gets bound up doing bit divisions of very large quantities of composite numbers all the even numbers plus the odd composites by the whole range of numbers up to that top number of ten raised to the sixteenth power for each prime that it can possibly produce. The above code works because it limits the computation to only the odd numbers and only does modulo divisions up to the square root of the current number being tested. Mersenne primes take their name from the 17th-century French scholar Marin Mersennewho compiled what was supposed to be a list of Mersenne primes with exponents up to The exponents listed by Mersenne were as follows: His list replicated the known primes of his time with exponents up to His next entry, 31, was correct, but the list then became largely incorrect, as Mersenne mistakenly included M67 and M which are composite and omitted M61, M89, and M which are prime.

Mersenne gave little indication how he came up with his list. This was the largest known prime number for 75 years, and the largest ever found by hand.

M61 was determined to be prime in by Ivan Mikheevich Pervushinthough Mersenne claimed it was composite, and for this reason it is sometimes called Pervushin's number. This was the second-largest known prime number, and it remained so until Lucas had shown another error in Mersenne's list in Without finding a factor, Lucas demonstrated that M67 is actually composite. 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.

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. 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.

## Java program to display prime numbers from 1 to and 1 to n

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 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, The find was verified on June 12, Although it is chronologically the 47th Mersenne prime to be discovered, it is smaller than the largest known at the time, which was the 45th to be discovered.

This fact leads to a proof of Euclid's theoremwhich asserts the infinitude of primes, distinct from the proof written by Euclid: A Mersenne prime cannot be a Wieferich prime.

Consequently, a prime number divides at most one prime-exponent Mersenne number,  so in other words the set of pernicious Mersenne numbers is pairwise coprime.

However, since p is congruent to 3 mod 4q is congruent to 7 mod 8 and therefore 2 is a quadratic residue mod q. All composite divisors of prime-exponent Mersenne numbers are strong pseudoprimes to the base 2.We will take a loop and divide number from 2 to number/2.

If the number is not divisible by any of the numbers then we will print it as prime number. New Fermat factor from FermatSearch!

## Loops - Prime numbers between 1 to in C Programming Language - Stack Overflow

2 +1 is a Factor of F !!! Roman Maznichenko discovered the third Fermat factor of this year! He used his Feromant_CUDA program running on a GTX(factoring) + 1 core Intel(Coffeelake) [email protected] (sieve) under Windows.

If the loop terminates because of break statement inside the if statement, the entered number is a nonprime number. The value of flag is 1 in this case. Visit this page to learn, how you can display all prime numbers between two intervals entered by the user.

There’s a popular story that Gauss, mathematician extraordinaire, had a lazy tranceformingnlp.com so-called educator wanted to keep the kids busy so he could take a nap; he asked the class to add the numbers 1 to Example to print all prime numbers between two numbers (entered by the user) in C++ Programming.

This problem is solved using nested for loop and if else statement. whether low is a prime number or not is checked and the value of low is incremented by 1 until low is equal to high.

A positive integer which is only divisible by 1 and itself is known as prime number. For example: 13 is a prime number because it is only divisible by 1 and 13 but, 15 is not prime number because it is divisible by 1, 3, 5 and

c++ - Printing prime numbers from 1 through - Stack Overflow