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Putnam
Putnam 1939
B3
Putnam 1939 B3
Putnam 1939 B3
Source:
August 20, 2021
Putnam
Problem Statement
Given
a
n
=
(
n
2
+
1
)
3
n
,
a_n = (n^2 + 1) 3^n,
a
n
=
(
n
2
+
1
)
3
n
,
find a recurrence relation
a
n
+
p
a
n
+
1
+
q
a
n
+
2
+
r
a
n
+
3
=
0.
a_n + p a_{n+1} + q a_{n+2} + r a_{n+3} = 0.
a
n
+
p
a
n
+
1
+
q
a
n
+
2
+
r
a
n
+
3
=
0.
Hence evaluate
∑
n
≥
0
a
n
x
n
.
\sum_{n\geq0} a_n x^n.
∑
n
≥
0
a
n
x
n
.
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