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A058166
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Triangle read by rows: T(n,k) = number of labeled semigroups of order n with k idempotents.
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3
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1, 4, 4, 24, 54, 35, 356, 1044, 1488, 604, 16585, 31620, 60900, 57900, 16727, 3461916, 1699290, 3345420, 4744380, 3128880, 681232, 6058301508, 265521354, 263429355, 439698420, 455785470, 222132666, 38187291
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table;
graph;
refs;
listen;
history;
text;
internal format)
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OFFSET
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1,2
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LINKS
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Table of n, a(n) for n=1..28.
Index entries for sequences related to semigroups
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EXAMPLE
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1; 4,4; 24,54,35; 356,1044,1488,604; ...
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CROSSREFS
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Row sums give A023814.
Sequence in context: A131978 A049614 A269186 * A092897 A269152 A269097
Adjacent sequences: A058163 A058164 A058165 * A058167 A058168 A058169
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KEYWORD
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nonn,tabl,hard
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AUTHOR
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Christian G. Bower, Nov 15 2000
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STATUS
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approved
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