OFFSET
1,10
REFERENCES
R. W. Robinson, Numerical implementation of graph counting algorithms, AGRC Grant, Math. Dept., Univ. Newcastle, Australia, 1978.
LINKS
R. W. Robinson, Rows 1 through 30, flattened
EXAMPLE
K M N gives the number N of unlabeled free bicolored trees with K nodes of one color and M nodes of the other color.
0 1 1
1 0 1
Total( 1) = 2
1 1 1
Total( 2) = 1
1 2 1
2 1 1
Total( 3) = 2
1 3 1
2 2 1
3 1 1
Total( 4) = 3
1 4 1
2 3 2
3 2 2
4 1 1
Total( 5) = 6
1 5 1
2 4 2
3 3 4
4 2 2
5 1 1
Total( 6) = 10
.
From Andrew Howroyd, Nov 02 2019: (Start)
Triangle for n >= 2, 1 <= k < n:
2 | 1;
3 | 1, 1;
4 | 1, 1, 1;
5 | 1, 2, 2, 1;
6 | 1, 2, 4, 2, 1;
7 | 1, 3, 7, 7, 3, 1;
8 | 1, 3, 10, 14, 10, 3, 1;
9 | 1, 4, 14, 28, 28, 14, 4, 1;
10 | 1, 4, 19, 45, 65, 45, 19, 4, 1;
11 | 1, 5, 24, 73, 132, 132, 73, 24, 5, 1;
12 | 1, 5, 30, 105, 242, 316, 242, 105, 30, 5, 1;
...
(End)
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
N. J. A. Sloane, Oct 19 2006
STATUS
approved