I'll put my thought process here because those equations look pretty arbitrary.

From that example grid of values of f, you can see the sum is 1*(n^{2} - (n-1)^{2)} + 2 * ((n-1)^{2} - (n-2)^{2)} + ... when you expand that out you get the sum of the first n squares. Which is the formula in summin (that Google lead me to).

For g, you can produce a chart of its value by taking an nxn square of n's, then subtracting the area of each square smaller than that. e.g. n*n*n - (n - 1)^{2} - (n - 2)^{2} -... which is the same as n*n*n - summin (n-1)

sumsum could be just the sum of the other two functions, but that's too simple. if you math it out, you get n*n*n + n*n. Much better.

## re: Daily Challenge #112 - Functions of Integers on the Cartesian Plane VIEW POST

FULL DISCUSSIONNo loops required!

I'll put my thought process here because those equations look pretty arbitrary.

From that example grid of values of f, you can see the sum is 1*(n

^{2}- (n-1)^{2)}+ 2 * ((n-1)^{2}- (n-2)^{2)}+ ... when you expand that out you get the sum of the first n squares. Which is the formula in`summin`

(that Google lead me to).For g, you can produce a chart of its value by taking an nxn square of n's, then subtracting the area of each square smaller than that. e.g. n*n*n - (n - 1)

^{2}- (n - 2)^{2}-... which is the same as n*n*n - summin (n-1)sumsum could be just the sum of the other two functions, but that's too simple. if you math it out, you get n*n*n + n*n. Much better.