A332405 - OEIS

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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.

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

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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

Table of n, a(n) for n=1..55.

Eric Weisstein's World of Mathematics, Irredundant Set

EXAMPLE

Triangle begins:

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;