An integer ?≥2n≥2 is called square-positive if there are ? consecutive positive integers whose sum is a square. Determine the first four square-positive integers.
So I have found the first four square-positive numbers, but I need to prove that why it 44 is not a square-positive number and I also need to write a general formula for determining whether a number is square-positive or not. I have tried to write the sum of consecutive positive integers like this ?+?+1+?+2+?+3....?−1 and I wrote it like this for all numbers, and part of the proof for why 44 isn't a square-positive number is that 4?+64a+6 is not divisible with 44. But I haven't got so far.
Here is my answer:
2 : 4 + 5 = 9 which is 3^2
3 : 2 + 3 + 4 = 9 which is 3^2
5: 18 + 19 + 20 + 21 + 22 = 100 which is 10^2
6: 35 + 36 + 37 + 38 + 39 + 40 = 225 which is 15^2
Interesting fact is that for all odd numbers and some even numbers like 6 and 10, you can find out which number is the first (the one you start with and then go forward here like 3, 2, 18 and 35) using this formula :
(I show it in an example because I still can't write it algebraically):
For example: the sum of 95 subsequent numbers is 5n + 10
(10^2 - 10) /5 = 18
So your first number is 18
And if you keep adding, 18 + 19 + 20 + 21 + 22 you get 100 which is 10^2, the same number you squared.
So I have found the first four square-positive numbers, but I need to prove that why it 44 is not a square-positive number and I also need to write a general formula for determining whether a number is square-positive or not. I have tried to write the sum of consecutive positive integers like this ?+?+1+?+2+?+3....?−1 and I wrote it like this for all numbers, and part of the proof for why 44 isn't a square-positive number is that 4?+64a+6 is not divisible with 44. But I haven't got so far.
Here is my answer:
2 : 4 + 5 = 9 which is 3^2
3 : 2 + 3 + 4 = 9 which is 3^2
5: 18 + 19 + 20 + 21 + 22 = 100 which is 10^2
6: 35 + 36 + 37 + 38 + 39 + 40 = 225 which is 15^2
Interesting fact is that for all odd numbers and some even numbers like 6 and 10, you can find out which number is the first (the one you start with and then go forward here like 3, 2, 18 and 35) using this formula :
(I show it in an example because I still can't write it algebraically):
For example: the sum of 95 subsequent numbers is 5n + 10
(10^2 - 10) /5 = 18
So your first number is 18
And if you keep adding, 18 + 19 + 20 + 21 + 22 you get 100 which is 10^2, the same number you squared.