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A332404
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Triangle read by rows: T(n,k) is the number of graphs on n unlabeled nodes with irredundance number k.
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5
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1, 1, 1, 2, 1, 1, 4, 5, 1, 1, 11, 16, 5, 1, 1, 34, 94, 21, 5, 1, 1, 156, 710, 150, 21, 5, 1, 1, 1044, 9419, 1691, 164, 21, 5, 1, 1, 12346, 221979, 38207, 1944, 164, 21, 5, 1, 1, 274668, 9907071, 1773452, 47802, 1983, 164, 21, 5, 1, 1
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OFFSET
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1,4
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COMMENTS
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The irredundance number of a graph is the minimum size of a maximal irredundant set.
For any graph the following relation holds:
irredundance number (this sequence)
<= independent domination number (A332402)
<= upper domination number (A332403)
<= upper irredundance number (A332405).
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LINKS
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FORMULA
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T(n,k) = T(n-1,k-1) for 2*(k-1) >= n.
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EXAMPLE
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Triangle begins:
1;
1, 1;
2, 1, 1;
4, 5, 1, 1;
11, 16, 5, 1, 1;
34, 94, 21, 5, 1, 1;
156, 710, 150, 21, 5, 1, 1;
1044, 9419, 1691, 164, 21, 5, 1, 1;
12346, 221979, 38207, 1944, 164, 21, 5, 1, 1;
274668, 9907071, 1773452, 47802, 1983, 164, 21, 5, 1, 1;
...
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CROSSREFS
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KEYWORD
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AUTHOR
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STATUS
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approved
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