MathDB

Find all the possible values of the sum of the digits of all the perfect squares.
[Commented by djimenez] Comment: I would rewrite it as follows: Let

f: \mathbb{N}\rightarrow \mathbb{N}

such that

f(n)

is the sum of all the digits of the number

n^2

. Find the image of

f

(where, by image it is understood the set of all

x

such that exists an

n

with

f(n)=x

Problem Statement