Goldbach's Conjecture states every even number can be written as a sum of two primes. This has not yet been proven but it appears highly likely. In fact, it seems that every number greater than 12 can be written as a sum of two primes in at least two different ways. For example:
A283392 | Integers m of the form |
Up to 40,000, the members of this sequence are 50, 146, 866, 2162, 4178, 8362, 14372, 17138, 19094, 22504, 25346, 26764, 27544 and 35074 (permalink).
For example: This is equivalent to finding the solutions to the two separate equations with and necessarily being consecutive primes: The algorithm that generated the earlier list is easily modified to accommodate different values of . Let's take the case of , , and where the following numbers (not listed in the OEIS) satisfy (permalink):
98, 482, 2314, 8966, 9766, 10562, 12148, 12962, 13066, 14372, 14548, 25588, 31202, 31414, 31846, 34082, 37174, 37588, 39526
An example is 98 where: Of course 98 itself cannot be written as sum of two consecutive primes because: Clearly (19, 79), (31, 67) and (37, 61) are not consecutive primes. However, by considering linear combinations of the two consecutive primes, we see (11, 13) and (5, 7) satisfy.
Here is another variation , , and where 38 numbers are generated in the range up to 40000. The numbers are (permalink):
407, 541, 1351, 1757, 1783, 2161, 4973, 6077, 6349, 6511, 6889, 7427, 8083, 8723, 10427, 11747, 12751, 13069, 13339, 14833, 18203, 20657, 20791, 21283, 24953, 25111, 29171, 29297, 29323, 31703, 33511, 34157, 35623, 36047, 37397, 37423, 38507, 39181
An example is 407 where: Yet another variations is , , and where 23 numbers are generated in the range up to 40000. The numbers are (permalink):
1123, 1157, 4327, 4621, 5671, 5987, 11867, 15877, 19111, 21451, 22157, 23477, 23731, 24257, 26887, 27097, 30199, 30367, 33707, 35773, 36961, 37031, 39607
An example is 1123 where: I'll leave it there but the permalink provides the opportunity to play around with other combinations of . The number properties described in this post are not base dependent and so are possibly of serious mathematical interests. It seems to be that there should be some practical applications of this technique as a useful way of decomposing or building composite numbers.
Here is an alternative algorithm that generates the same output but uses a different method. It can be used to discover numbers that are linear combinations of two consecutive primes without being equal to a linear combination of two other consecutive primes. For example, it will show that 844 is a linear combination of 3 times 103 and 5 times 107. In other word we have solved the linear equation: where and are prime and is the next prime after .
Obviously, by choosing prime values of and we end up with a composite number that is the sum of the products of two pairs of primes. Thus for 844 we have: which defines the number in the similar way to its prime factorisation: Unlike the product of a number's prime factors however, this representation is not necessarily unique as we've seen that some numbers have more than one representation as the sum of the products of two pairs of primes e.g. 2162 (permalink):
No comments:
Post a Comment