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A058122
Number of self-converse idempotent semigroups of order n.
2
1, 1, 1, 2, 6, 19, 68, 285
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OFFSET
0,4
LINKS
Table of n, a(n) for n=0..7.
Index entries for sequences related to semigroups
CROSSREFS
Main diagonal of
A058118
.
Sequence in context:
A150103
A150104
A145868
*
A150105
A150106
A150107
Adjacent sequences:
A058119
A058120
A058121
*
A058123
A058124
A058125
KEYWORD
nonn
,
hard
AUTHOR
Christian G. Bower
, Nov 10 2000
STATUS
approved
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Last modified August 16 21:21 EDT 2024. Contains 375191 sequences. (Running on oeis4.)