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Contests
National and Regional Contests
Greece Contests
Greece National Olympiad
1996 Greece National Olympiad
4
4
Part of
1996 Greece National Olympiad
Problems
(1)
Number of functions
Source: Greek national M.O. 1996, Final Round, problem 4
11/20/2011
Find the number of functions
f
:
{
1
,
2
,
.
.
.
,
n
}
ā
{
1995
,
1996
}
f : \{1, 2, . . . , n\} \to \{1995, 1996\}
f
:
{
1
,
2
,
...
,
n
}
ā
{
1995
,
1996
}
such that
f
(
1
)
+
f
(
2
)
+
.
.
.
+
f
(
1996
)
f(1) + f(2) + ... + f(1996)
f
(
1
)
+
f
(
2
)
+
...
+
f
(
1996
)
is odd.
function
combinatorics unsolved
combinatorics