OFFSET
0,3
COMMENTS
EXAMPLE
Illustration of a(4) = -6.
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. Compositions of 4 Overpartitions of 4
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. _ _ _ _ _ _ _ _
1 |_| | | | 1, 1, 1, 1 |.| | | | 1', 1, 1, 1
2 |_ _| | | 2, 1, 1 |_| | | | 1, 1, 1, 1
3 |_| | | 1, 2, 1 | .|.| | 2', 1', 1
4 |_ _ _| | 3, 1 | |.| | 2, 1', 1
5 |_| | | 1, 1, 2 | .| | | 2', 1, 1
6 |_ _| | 2, 2 |_ _| | | 2, 1, 1
7 |_| | 1, 3 | .|.| 3', 1
8 |_ _ _ _| 4 | |.| 3, 1
9 | .| | 3', 1
10 |_ _ _| | 3, 1
11 | .| | 2', 2
12 |_ _| | 2, 2
13 | .| 4'
14 |_ _ _ _| 4
.
There are 8 compositions of 4 and there are 14 overpartitions of 4, so a(4) = 8 - 14 = -6.
CROSSREFS
KEYWORD
sign
AUTHOR
Omar E. Pol, Feb 02 2014
STATUS
approved