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National and Regional Contests
Switzerland Contests
Switzerland Team Selection Test
2000 Switzerland Team Selection Test
4
4
Part of
2000 Switzerland Team Selection Test
Problems
(1)
q(q(q(2000^{2000}))) , where q(n) is sum of digits of n
Source: Switzerland - Swiss TST 2000 p4
2/19/2020
Let
q
(
n
)
q(n)
q
(
n
)
denote the sum of the digits of a natural number
n
n
n
. Determine
q
(
q
(
q
(
200
0
2000
)
)
)
q(q(q(2000^{2000})))
q
(
q
(
q
(
200
0
2000
)))
.
Sum
sum of digits
number theory