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PEN Problems
PEN O Problems
47
47
Part of
PEN O Problems
Problems
(1)
O 47
Source:
5/25/2007
Let
S
S
S
be the set of all composite positive odd integers less than
79
79
79
. [*] Show that
S
S
S
may be written as the union of three (not necessarily disjoint) arithmetic progressions.[*] Show that
S
S
S
cannot be written as the union of two arithmetic progressions.