A350488 - OEIS

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A350488

Triangle read by rows: T(n,k) is the number of acyclic digraphs on n unlabeled nodes with k arcs and a global source, n >= 1, k = 0..n*(n-1)/2.

1, 0, 1, 0, 0, 2, 1, 0, 0, 0, 4, 6, 5, 1, 0, 0, 0, 0, 9, 25, 47, 46, 27, 9, 1, 0, 0, 0, 0, 0, 20, 95, 297, 582, 783, 738, 501, 235, 75, 14, 1, 0, 0, 0, 0, 0, 0, 48, 337, 1575, 4941, 11295, 19404, 25847, 26966, 22195, 14380, 7280, 2831, 816, 165, 20, 1

(list; graph; refs; listen; history; text; internal format)

OFFSET

1,6

LINKS

Andrew Howroyd, Table of n, a(n) for n = 1..1350 (rows 1..20)

EXAMPLE

Triangle begins:

[1] 1;

[2] 0, 1;

[3] 0, 0, 2, 1;

[4] 0, 0, 0, 4, 6, 5, 1;

[5] 0, 0, 0, 0, 9, 25, 47, 46, 27, 9, 1;