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A332405
Triangle read by rows: T(n,k) is the number of graphs on n unlabeled nodes with upper irredundance number k.
4
1, 1, 1, 1, 2, 1, 1, 6, 3, 1, 1, 13, 15, 4, 1, 1, 36, 83, 30, 5, 1, 1, 101, 582, 302, 51, 6, 1, 1, 364, 6025, 5025, 843, 80, 7, 1, 1, 1511, 99503, 144371, 27160, 1996, 117, 8, 1, 1, 7917, 2706030, 7441332, 1733212, 112291, 4211, 164, 9, 1
OFFSET
1,5
COMMENTS
First differs from A332403 in row 7.
The upper irredundance number of a graph is the maximum size of an irredundant set. For any graph the upper irredundance number is greater than or equal to the upper domination number (A332403).
LINKS
Eric Weisstein's World of Mathematics, Irredundant Set
EXAMPLE
Triangle begins:
1;
1, 1;
1, 2, 1;
1, 6, 3, 1;
1, 13, 15, 4, 1;
1, 36, 83, 30, 5, 1;
1, 101, 582, 302, 51, 6, 1;
1, 364, 6025, 5025, 843, 80, 7, 1;
1, 1511, 99503, 144371, 27160, 1996, 117, 8, 1;
1, 7917, 2706030, 7441332, 1733212, 112291, 4211, 164, 9, 1;
...
CROSSREFS
Row sums are A000088.
Sequence in context: A181621 A307070 A084268 * A332403 A263341 A201198
KEYWORD
nonn,tabl
AUTHOR
Andrew Howroyd, Feb 11 2020
STATUS
approved