Equation with three consecutive prime numbers

In summary, the equation np_n+(n+1)p_{n+1}+(n+2)p_{n+2}=p^2_{n+2} has a solution for n=2, p_2=3, p_3=5, p_4=7. It is also possible that there are other solutions, but it has been proven that there can't be a solution for n \geq 10. This is because 3(n+2) \lt p_{n+2} for n \geq 10. The reasoning for this is that if we plug in n=10, we get a value of 36 for 3(n+2) and a value of
  • #1
Dacu
8
2
Solve the equation [tex]np_n+(n+1)p_{n+1}+(n+2)p_{n+2}=p^2_{n+2}[/tex] where [tex]n\in \mathbb N^*[/tex] and [tex]p_n , p_{n+1} , p_{n+2}[/tex] are three consecutive prime numbers.
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A solution is [tex]n=2,p_2=3,p_3=5,p_4=7.[/tex]
May be other solutions?
 
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  • #2
Well, you know that there can't be a solution with [itex]n \geq 10[/itex]. So there are only 10 possibilities to check.

Here's my reasoning:
[itex]n p_n + (n+1) p_{n+1} + (n+2) p_{n+2} \leq 3 (n+2) p_{n+2}[/itex]

So if [itex]n p_n + (n+1) p_{n+1} + (n+2) p_{n+2} = p_{n+2}^2[/itex], that means

[itex]3 (n+2) p_{n+2} \geq p_{n+2}^2[/itex]

which means

[itex]3 (n+2) \geq p_{n+2}[/itex]

I'm pretty sure that for [itex]n \geq 10[/itex],
[itex]3(n+2) \lt p_{n+2}[/itex]

(When [itex]n=10[/itex], [itex]3(n+2) = 36[/itex] and [itex]p_{n+2} = 37[/itex])
 
  • #3
My reasoning:
From the original equation we get [tex](n+2)^2+4np_n+4(n+1)p_{n+1}=m^2[/tex] where [tex]m\in \mathbb N^*.[/tex]
Is there such a natural number [tex]m?[/tex]
 
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1. What is an equation with three consecutive prime numbers?

An equation with three consecutive prime numbers is an algebraic expression that contains three consecutive prime numbers as its variables. For example, the equation x + (x+2) + (x+4) = 3 + 5 + 7 is an equation with three consecutive prime numbers.

2. How do you solve an equation with three consecutive prime numbers?

To solve an equation with three consecutive prime numbers, you need to first identify the three consecutive prime numbers. Then, you can simplify the equation by combining like terms and using basic algebraic techniques such as distribution and elimination. Finally, you can solve for the variable using the appropriate operations.

3. What makes an equation with three consecutive prime numbers special?

An equation with three consecutive prime numbers is special because it involves the use of prime numbers, which are unique and have special properties. Additionally, the consecutive nature of the numbers adds an element of challenge and complexity to the equation, making it an interesting problem to solve.

4. Can an equation with three consecutive prime numbers have more than one solution?

Yes, an equation with three consecutive prime numbers can have more than one solution. Depending on the specific equation, there may be multiple values for the variable that satisfy the given equation. This is especially true if the equation involves variables with exponents or higher degrees.

5. How can an equation with three consecutive prime numbers be applied in real life?

An equation with three consecutive prime numbers can be applied in real life in various fields such as cryptography, computer science, and physics. For example, in cryptography, an equation with three consecutive prime numbers can be used to create secure encryption algorithms. In physics, it can be used to model natural phenomena that involve prime numbers, such as the distribution of prime numbers in the universe.

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