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A121921
A102897
(n) - 1.
1
1, 3, 13, 121, 4959, 2771103, 151947502947
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OFFSET
0,2
COMMENTS
Same as
A102897
, but counts nonempty set systems.
LINKS
Table of n, a(n) for n=0..6.
CROSSREFS
Sequence in context:
A057865
A344210
A260847
*
A191955
A241458
A302861
Adjacent sequences:
A121918
A121919
A121920
*
A121922
A121923
A121924
KEYWORD
nonn
AUTHOR
N. J. A. Sloane
, Mar 17 2007
STATUS
approved
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Last modified May 2 23:14 EDT 2024. Contains 372203 sequences. (Running on oeis4.)