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Moldova Team Selection Test
2017 Moldova Team Selection Test
10
10
Part of
2017 Moldova Team Selection Test
Problems
(1)
MDA TST B10, floor function problem
Source: Moldova 2017 TSTST, B10
3/20/2017
Let
p
p
p
be an odd prime. Prove that the number
⌊
(
5
+
2
)
p
−
2
p
+
1
⌋
\left\lfloor \left(\sqrt{5}+2\right)^{p}-2^{p+1}\right\rfloor
⌊
(
5
+
2
)
p
−
2
p
+
1
⌋
is divisible by
20
p
20p
20
p
.
number theory