If you don't remember prime numbers here are the first ones:
2,3,5,7,11,13,17,19,23,29
2006-08-30 17:49:22 · 11 answers · asked by ♥ Arvizu16 3 in Science & Mathematics ➔ Mathematics
There is no formula and there never will be. That's the awe and mystery of primes.
You can get a few of then by subtracting consecutive perfect cubes, but this ultimately fails -- and soon!
Try (x^3) minus (x-1)^3.
2006-08-30 17:55:19 · answer #1 · answered by Anonymous · 0⤊ 0⤋
Eratosthenes (275-194 B.C., Greece) devised a 'sieve' to discover prime numbers. A sieve is like a strainer that you drain spaghetti through when it is done cooking. The water drains out, leaving your spaghetti behind. Eratosthenes's sieve drains out composite numbers and leaves prime numbers behind.
To use the sieve of Eratosthenes to find the prime numbers up to 100, make a chart of the first one hundred whole numbers (1-100):
1 2 3 4 5 6 7 8 9 10
11 12 13 14 15 16 17 18 19 20
21 22 23 24 25 26 27 28 29 30
31 32 33 34 35 36 37 38 39 40
41 42 43 44 45 46 47 48 49 50
51 52 53 54 55 56 57 58 59 60
61 62 63 64 65 66 67 68 69 70
71 72 73 74 75 76 77 78 79 80
81 82 83 84 85 86 87 88 89 90
91 92 93 94 95 96 97 98 99 100
Cross out 1, because it is not prime.
Circle 2, because it is the smallest positive even prime. Now cross out every multiple of 2; in other words, cross out every second number.
Circle 3, the next prime. Then cross out all of the multiples of 3; in other words, every third number. Some, like 6, may have already been crossed out because they are multiples of 2.
Circle the next open number, 5. Now cross out all of the multiples of 5, or every 5th number.
Continue doing this until all the numbers through 100 have either been circled or crossed out. You have just circled all the prime numbers from 1 to 100!
2006-08-31 00:54:36 · answer #2 · answered by saini160179 2 · 1⤊ 0⤋
There is no formula. You can test a number to find out if it's prime, but there is no way to generate them all by a formula. There's not even a way to calculate how many there are between 1 and x. (The Riemann Hypothesis answering this question is one of the major unproven ideas in mathematics.)
2006-08-31 01:12:19 · answer #3 · answered by Art_333 2 · 1⤊ 0⤋
There are in fact formulas for prime numbers, but they are so cumbersome they are literally useless. They generally rely on knowing previous prime numbers to get the next ones, so you get a sort of tautology and are back to square one. There are however approximations. These approximations generally get better the bigger the prime number is. One approximation is
P(n) ~ n*Log(n)+n*Log(Log(n))-n
where P(n) is the n'th prime number and Log is the natural log. If n is very very big, you can presume that
P(n) ~ n*Log(n)
2006-08-31 01:16:51 · answer #4 · answered by Blahh 2 · 0⤊ 0⤋
I think it a weird number that can not be factored outside of itself and with ONE of course. One should be considered the "Prime Number" ONLY as it can factor any other number including itself "Evenly". Hmmm, seems they should call them; "Abnormal Numbers"!
Not really a Formula, well, then again, maybe there is?
I not sure what "saini160179" said, but that some deep sh*t. But, it sure sound like a best answer to me. I going to go drink a Beer and "sieve" those numbers!
2006-08-31 00:57:39 · answer #5 · answered by Snaglefritz 7 · 0⤊ 1⤋
I can't recall the actual equation for finding prime numbers but if I remember correctly, prime numbers are only divisible by itself and the number 1.
2006-08-31 00:56:54 · answer #6 · answered by tropicvibe 3 · 0⤊ 1⤋
Prime numbers are numbers that can't be divided by any number other than 1 ( with the exception of 2). Get it
2006-08-31 00:55:46 · answer #7 · answered by MenudoPie 3 · 0⤊ 1⤋
If a number is prime it has no other factors than one and itself.
2006-08-31 00:53:15 · answer #8 · answered by Anonymous · 0⤊ 0⤋
there is NO formula for prime numbers....
sorry,
2006-08-31 01:03:41 · answer #9 · answered by locuaz 7 · 1⤊ 0⤋
37, n so on use the web site below.
2006-08-31 00:56:08 · answer #10 · answered by you 2 · 0⤊ 1⤋