#### Topic: To find the amount formula

The square on the screen with square  with the side n  is given. How to describe such square words, I do not know, but on a picture all should be clear. To find the amount formula  in dependence from n: f (n) For example, Here, at n=4 , like, 25. Separate plus that who can correctly describe the task without a picture.

#### Re: To find the amount formula

Hello, Titus, you wrote: T> For example, T> Here, at n=4 , like, 25. At first sight, the mathematical induction method arises. It works?

#### Re: To find the amount formula

Hello, Titus, you wrote: T> the square on the screen with square  with the side n  Is given. T> How to describe such square words, I do not know, but on a picture all should be clear. T> to find the amount formula  in dependence from n: f (n) T> Image: Romb. PNG T> For example, T> Here, at n=4 , like, 25. T> Separate plus that who can correctly describe the task without a picture. n^2 + (n-1) ^2

#### Re: To find the amount formula

Hello, Qulac, you wrote: Q> n^2 + (n-1) ^2 it is similar on

#### Re: To find the amount formula

Hello, Titus, you wrote: T> to Find the amount formula  in dependence from n: f (n) Sequence of an amount  depending on length of the side of a square: 1, 5, 13, 25, 41,61. It is an arithmetical progression of the second order. A difference between members of a row: 4 * (n-1). 0, 4, 8, 12, 16, 20 It is an arithmetical progression of first order. The total n members of a progression of first order: sum = (2*a1+4 * (n-1)) *n/2=2n^2-2n/n th member of an initial progression: f (n) = 2*n^2-2*n+1