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Nordic
2023 Nordic
P3
P3
Part of
2023 Nordic
Problems
(1)
Another NT FE
Source: Nordic MC 2023 P3
4/21/2023
Find all functions
f
:
N
0
→
Z
f:\mathbb{N}_0 \to \mathbb{Z}
f
:
N
0
→
Z
such that
f
(
k
)
−
f
(
l
)
∣
k
2
−
l
2
f(k)-f(l) \mid k^2-l^2
f
(
k
)
−
f
(
l
)
∣
k
2
−
l
2
for all integers
k
,
l
≥
0
k, l \geq 0
k
,
l
≥
0
.
number theory