OFFSET
1,4
LINKS
Don Knuth, Rows n = 1..16, flattened
Don Knuth, The first 16 rows.
EXAMPLE
For example, when n=4, the 31 weakly connected graphs have respectively 1, 6, 15, 9 cases with 0, 1, 2, and 3 arcs (as in the example given for A350608).
Triangle T(n,k) begins:
1;
1;
1, 3;
1, 6, 15, 9;
1, 10, 45, 120, 162, 109, 27;
1, 15, 105, 455, 1365, 2755, 3738, 3353, 1889, 600, 81;
...
CROSSREFS
KEYWORD
nonn,tabf
AUTHOR
Don Knuth, Jan 16 2022
STATUS
approved