MathDB
Problems
Contests
Undergraduate contests
Putnam
1985 Putnam
A4
Putnam 1985 A4
Putnam 1985 A4
Source:
August 5, 2019
Putnam
Problem Statement
Define a sequence
{
a
i
}
\left\{a_{i}\right\}
{
a
i
}
by
a
1
=
3
a_{1}=3
a
1
=
3
and
a
i
+
1
=
3
a
i
a_{i+1}=3^{a_{i}}
a
i
+
1
=
3
a
i
for
i
≥
1.
i \geq 1.
i
≥
1.
Which integers between
00
00
00
and
99
99
99
inclusive occur as the last two digits in the decimal expansion of infinitely many
a
i
?
a_{i} ?
a
i
?
Back to Problems
View on AoPS