Project Euler – Problem 6

From the Project Euler

Problem 6:
The sum of the squares of the first ten natural numbers is,
1^2 + 2^2 + … + 10^2 = 385
The square of the sum of the first ten natural numbers is,
(1 + 2 + … + 10)^2 = 55^2 = 3025
Hence the difference between the sum of the squares of the first ten natural numbers and the square of the sum is 3025 – 385 = 2640.
Find the difference between the sum of the squares of the first one hundred natural numbers and the square of the sum.

checked

very easy.

luni66

Project Euler – Problem 5

From the Project Euler

Problem 5:
2520 is the smallest number that can be divided by each of the numbers from 1 to 10 without any remainder.
What is the smallest positive number that is evenly divisible by all of the numbers from 1 to 20?

checked

It ‘s the least common multiple of the numbers between 2 and 20.

luni66

Project Euler

I decided to start with Project Euler.
Until now I have solved the first two problems, very easy:

Prolem 1
Add all the natural numbers below one thousand that are multiples of 3 or 5.

Problem 2
By considering the terms in the Fibonacci sequence whose values do not exceed four million, find the sum of the even-valued terms.

luni66