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A058116
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Triangle: Number of commutative semigroups of order n with k idempotents.
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4
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1, 2, 1, 5, 5, 2, 16, 23, 14, 5, 62, 106, 93, 49, 15, 342, 544, 582, 422, 200, 53, 3435, 3380, 3773, 3360, 2178, 943, 222
(list; table; graph; refs; listen; history; internal format)
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OFFSET
| 1,2
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LINKS
| Index entries for sequences related to semigroups
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EXAMPLE
| 1; 2,1; 5,5,2; 16,23,14,5; 62,106,93,49,15; ...
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CROSSREFS
| Row sums give A001426. Main diagonal: A006966(n+1). Column 1: A058117.
Sequence in context: A046757 A118244 A108410 * A058118 A124226 A193536
Adjacent sequences: A058113 A058114 A058115 * A058117 A058118 A058119
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KEYWORD
| nonn,tabl,hard
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AUTHOR
| Christian G. Bower (bowerc(AT)usa.net), Nov 09 2000
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