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Ireland National Math Olympiad
2023 Irish Math Olympiad
P6
P6
Part of
2023 Irish Math Olympiad
Problems
(1)
Sum of digits is a square
Source: Irish Mathematical Olympiad 2023 Problem 6
5/14/2023
A positive integer is totally square is the sum of its digits (written in base
10
10
10
) is a square number. For example,
13
13
13
is totally square because
1
+
3
=
2
2
1 + 3 = 2^2
1
+
3
=
2
2
, but
16
16
16
is not totally square.Show that there are infinitely many positive integers that are not the sum of two totally square integers.
number theory